Roll Dart SDK from 594434d5a0b5 to 92315c4b2dc2 (1 revision) (#20356)

https://dart.googlesource.com/external/github.com/flutter/engine/+/5848e57a76ea021faa28536d436a72b6da105bc8
diff --git a/commits.json b/commits.json
index 71fe247..d48409b 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
-  "external/github.com/flutter/engine":"c87706195c8b436633d0e2911a81f2eab7275ede",
+  "external/github.com/flutter/engine":"5848e57a76ea021faa28536d436a72b6da105bc8",
   "external/github.com/flutter/flutter":"4aed97681233a181ef8a135ed2809338473cbe11",
   "sdk":"92315c4b2dc24c13ce681a34992477991dafce48"
 }
\ No newline at end of file