Bump to latest mono_repo - use latest actions (#561)

Closes https://github.com/google/protobuf.dart/pull/550
Closes https://github.com/google/protobuf.dart/pull/560
diff --git a/.github/workflows/dart.yml b/.github/workflows/dart.yml
index 837a5f9..b125307 100644
--- a/.github/workflows/dart.yml
+++ b/.github/workflows/dart.yml
@@ -1,4 +1,4 @@
-# Created with package:mono_repo v5.0.4
+# Created with package:mono_repo v5.0.5
 name: Dart CI
 on:
   push:
@@ -19,7 +19,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:stable"
@@ -30,9 +30,9 @@
         with:
           sdk: stable
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: mono_repo self validate
-        run: dart pub global activate mono_repo 5.0.4
+        run: dart pub global activate mono_repo 5.0.5
       - name: mono_repo self validate
         run: dart pub global run mono_repo generate --validate
   job_002:
@@ -40,7 +40,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:2.12.0;packages:protobuf;commands:analyze_1-analyze_2"
@@ -53,7 +53,7 @@
         with:
           sdk: "2.12.0"
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -72,7 +72,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:dev;packages:api_benchmark-query_benchmark;commands:format-command_0-command_1-analyze_0"
@@ -85,7 +85,7 @@
         with:
           sdk: dev
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: api_benchmark_pub_upgrade
         name: api_benchmark; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -133,7 +133,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:dev;packages:protobuf;commands:format-analyze_0"
@@ -146,7 +146,7 @@
         with:
           sdk: dev
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -165,7 +165,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:dev;packages:protoc_plugin;commands:format-command_0-command_2-analyze_0"
@@ -178,7 +178,7 @@
         with:
           sdk: dev
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protoc_plugin_pub_upgrade
         name: protoc_plugin; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -205,7 +205,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:2.12.0;packages:protobuf;commands:test"
@@ -218,7 +218,7 @@
         with:
           sdk: "2.12.0"
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -239,7 +239,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:2.12.0;packages:protoc_plugin;commands:command_0-command_2-test"
@@ -252,7 +252,7 @@
         with:
           sdk: "2.12.0"
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protoc_plugin_pub_upgrade
         name: protoc_plugin; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -281,7 +281,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:dev;packages:protobuf;commands:test"
@@ -294,7 +294,7 @@
         with:
           sdk: dev
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -315,7 +315,7 @@
     runs-on: ubuntu-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:ubuntu-latest;pub-cache-hosted;dart:dev;packages:protoc_plugin;commands:command_0-command_2-test"
@@ -328,7 +328,7 @@
         with:
           sdk: dev
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protoc_plugin_pub_upgrade
         name: protoc_plugin; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -357,7 +357,7 @@
     runs-on: macos-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:macos-latest;pub-cache-hosted;dart:2.12.0;packages:protobuf;commands:test"
@@ -370,7 +370,7 @@
         with:
           sdk: "2.12.0"
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -391,7 +391,7 @@
     runs-on: macos-latest
     steps:
       - name: Cache Pub hosted dependencies
-        uses: actions/cache@v2.1.6
+        uses: actions/cache@v2.1.7
         with:
           path: "~/.pub-cache/hosted"
           key: "os:macos-latest;pub-cache-hosted;dart:dev;packages:protobuf;commands:test"
@@ -404,7 +404,7 @@
         with:
           sdk: dev
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -428,7 +428,7 @@
         with:
           sdk: "2.12.0"
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
@@ -452,7 +452,7 @@
         with:
           sdk: dev
       - id: checkout
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - id: protobuf_pub_upgrade
         name: protobuf; dart pub upgrade
         if: "always() && steps.checkout.conclusion == 'success'"
diff --git a/tool/ci.sh b/tool/ci.sh
index cf5b3b4..93a4062 100755
--- a/tool/ci.sh
+++ b/tool/ci.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# Created with package:mono_repo v5.0.4
+# Created with package:mono_repo v5.0.5
 
 # Support built in commands on windows out of the box.
 # When it is a flutter repo (check the pubspec.yaml for "sdk: flutter")