Roll Dart SDK from 9a0f141e9a67 to 4ec0cf16c47c (1 revision)

https://dart.googlesource.com/sdk.git/+log/9a0f141e9a67..4ec0cf16c47c

2024-04-25 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.5.0-98.0.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 dart-vm-team@google.com,jimgraham@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://issues.skia.org/issues/new?component=1389291&template=1850622

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

Author: skia-flutter-autoroll

DEPS

@@ -62,7 +62,7 @@ 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': '9a0f141e9a67ff1587e0ddee79104d8def3b3bd0',
+  'dart_revision': '4ec0cf16c47ca8c1cf92d783f37841581f63e6fb',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py