Unpin mac_toolchain version (#48994)

mac_toolchain has been updated to no longer have 2 minute slowdown (https://github.com/flutter/flutter/issues/138109), so unpin to use the latest version.

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style
diff --git a/.ci.yaml b/.ci.yaml
index f4480ea..0f6e4f7 100644
--- a/.ci.yaml
+++ b/.ci.yaml
@@ -32,12 +32,9 @@
       device_type: none
       cpu: x86
       os: Mac-12|Mac-13
-      # TODO(vashworth): Remove specific toolchain_ver once https://github.com/flutter/flutter/issues/138109 is resolved.
       $flutter/osx_sdk : >-
         {
-          "sdk_version": "14e300c",
-          "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-          "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+          "sdk_version": "14e300c"
         }
     dimensions:
       mac_model: "Macmini8,1|Macmini9,1"
@@ -366,12 +363,9 @@
         [
           {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
         ]
-      # TODO(vashworth): Remove specific toolchain_ver once https://github.com/flutter/flutter/issues/138109 is resolved.
       $flutter/osx_sdk : >-
         {
-          "sdk_version": "14e300c",
-          "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-          "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+          "sdk_version": "14e300c"
         }
     drone_dimensions:
       - os=Mac-12|Mac-13
@@ -390,12 +384,9 @@
       add_recipes_cq: "true"
       release_build: "true"
       config_name: mac_ios_engine
-      # TODO(vashworth): Remove specific toolchain_ver once https://github.com/flutter/flutter/issues/138109 is resolved.
       $flutter/osx_sdk : >-
         {
-          "sdk_version": "14e300c",
-          "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-          "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+          "sdk_version": "14e300c"
         }
     drone_dimensions:
       - os=Mac-12|Mac-13
diff --git a/ci/builders/mac_android_aot_engine.json b/ci/builders/mac_android_aot_engine.json
index 5704a2b..962250d 100644
--- a/ci/builders/mac_android_aot_engine.json
+++ b/ci/builders/mac_android_aot_engine.json
@@ -35,9 +35,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -77,9 +75,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -119,9 +115,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -160,9 +154,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -202,9 +194,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -244,9 +234,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         }
diff --git a/ci/builders/mac_host_engine.json b/ci/builders/mac_host_engine.json
index c00f8a5..8642c1b 100644
--- a/ci/builders/mac_host_engine.json
+++ b/ci/builders/mac_host_engine.json
@@ -47,9 +47,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             },
             "tests": [
@@ -108,9 +106,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             },
             "tests": [
@@ -180,9 +176,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             },
             "tests": [
@@ -243,9 +237,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -288,9 +280,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -335,9 +325,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         }
diff --git a/ci/builders/mac_ios_engine.json b/ci/builders/mac_ios_engine.json
index 67d43aa..08cc3ad 100644
--- a/ci/builders/mac_ios_engine.json
+++ b/ci/builders/mac_ios_engine.json
@@ -19,9 +19,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -45,9 +43,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -71,9 +67,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -98,9 +92,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -125,9 +117,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -151,9 +141,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -178,9 +166,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -205,9 +191,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -233,9 +217,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -261,9 +243,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         }
diff --git a/ci/builders/mac_unopt.json b/ci/builders/mac_unopt.json
index 74aec4e..ae72400 100644
--- a/ci/builders/mac_unopt.json
+++ b/ci/builders/mac_unopt.json
@@ -33,9 +33,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             },
             "tests": [
@@ -68,9 +66,7 @@
                         "ios-16-4_14e300c",
                         "ios-16-2_14c18"
                     ],
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             },
             "drone_dimensions": [
@@ -156,9 +152,7 @@
             },
             "properties": {
                 "$flutter/osx_sdk": {
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             }
         },
@@ -178,9 +172,7 @@
                         "ios-16-4_14e300c",
                         "ios-16-2_14c18"
                     ],
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             },
             "drone_dimensions": [
@@ -250,9 +242,7 @@
                         "ios-16-4_14e300c",
                         "ios-16-2_14c18"
                     ],
-                    "sdk_version": "14e300c",
-                    "toolchain_ver_arm": "JiMOaZvCH66lnGWMJdLScE-7lkUnKaw3COdWwqXmjWEC",
-                    "toolchain_ver_intel": "Zp2HmSx7_-pu-yHqYqzoEpo0JRwNZGGwSj5V1SnLFmoC"
+                    "sdk_version": "14e300c"
                 }
             },
             "drone_dimensions": [