Roll Dart SDK from 4a239aa to 2f0c186 (1 revision) (#36679)

Author: skia-flutter-autoroll

DEPS

@@ -43,7 +43,7 @@ vars = {
   # Dart is: https://github.com/dart-lang/sdk/blob/main/DEPS.
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': '4a239aa9685fb7351193224be0a9be71ecf151c8',
+  'dart_revision': '2f0c186d3b10169bb58964d3dea295c1825ff780',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py