Roll Dart SDK from b1eb743f97f5 to ab60afc99bcb (1 revision) (flutter#167396)

https://dart.googlesource.com/sdk.git/+log/b1eb743f97f5..ab60afc99bcb

2025-04-18 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com
Version 3.9.0-31.0.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
Please CC codefu@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:
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:
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Author: engine-flutter-autoroll

DEPS

@@ -56,7 +56,7 @@ 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': 'b1eb743f97f5615db73e418b9ef5beea392a2a2e',
+  'dart_revision': 'ab60afc99bcb5476270812baf1ae1e71e85019e4',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py

engine/src/flutter/sky/packages/sky_engine/LICENSE

@@ -30447,7 +30447,7 @@ Exhibit B - "Incompatible With Secondary Licenses" Notice
   This Source Code Form is "Incompatible With Secondary Licenses", as
   defined by the Mozilla Public License, v. 2.0.
 
-You may obtain a copy of this library's Source Code Form from: https://dart.googlesource.com/sdk/+/b1eb743f97f5615db73e418b9ef5beea392a2a2e
+You may obtain a copy of this library's Source Code Form from: https://dart.googlesource.com/sdk/+/ab60afc99bcb5476270812baf1ae1e71e85019e4
 /third_party/fallback_root_certificates/
 
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