Roll Dart SDK from a31c331ed648 to a3a9d7af0cc2 (1 revision) (flutter#30127)

Author: skia-flutter-autoroll

DEPS

@@ -39,7 +39,7 @@ 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': 'a31c331ed648f96e3f7a7aac11034b233e224231',
+  'dart_revision': 'a3a9d7af0cc213ad7b0c278e3b9210b1a9a8c797',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -308,7 +308,7 @@ deps = {
    Var('dart_git') + '/sse.git@9084339389eb441d0c0518cddac211a097e78657',
 
   'src/third_party/dart/third_party/pkg/stack_trace':
-   Var('dart_git') + '/stack_trace.git@6788afc61875079b71b3d1c3e65aeaa6a25cbc2f',
+   Var('dart_git') + '/stack_trace.git@5220580872625ddee41e9ca9a5f3364789b2f0f6',
 
   'src/third_party/dart/third_party/pkg/stream_channel':
    Var('dart_git') + '/stream_channel.git@3fa3e40c75c210d617b8b943b9b8f580e9866a89',

ci/licenses_golden/licenses_third_party

@@ -1,4 +1,4 @@
-Signature: 8d34804d2669f68c73f83bdd8f094040
+Signature: 1255f544e7ab5c6f906d1afb5e35fd9b
 
 UNUSED LICENSES: