Roll Dart SDK from 2465228c0c21 to c4e9794df8af (1 revision) (flutter/engine#42831)

https://dart.googlesource.com/sdk.git/+log/2465228c0c21..c4e9794df8af

2023-06-13 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.1.0-207.0.dev

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dart-sdk-flutter-engine
Please CC chinmaygarde@google.com,dart-vm-team@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in Flutter Engine: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

DEPS

@@ -53,7 +53,7 @@ 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': '2465228c0c216c689f641cdb0acb61a37a4847fe',
+  'dart_revision': 'c4e9794df8af50a430878b12369d93e5bc6e815d',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -425,7 +425,7 @@ deps = {
    Var('dart_git') + '/mockito.git@1d6064adf043d1fce013d2d205a3fdc655c90043',
 
   'src/third_party/dart/third_party/pkg/native':
-   Var('dart_git') + '/native.git@78cf286e15aec57b51a1bbbbcaada5216ddc626a',
+   Var('dart_git') + '/native.git@2de88135e25577d851c95b04af0ceb74b706f285',
 
   'src/third_party/dart/third_party/pkg/package_config':
    Var('dart_git') + '/package_config.git@203de2022af26b3ab2bcec18cc49614d9e502897',