Roll Dart SDK from 83c6b6124380 to 7b645442db0f (1 revision) (flutter#175086)

https://dart.googlesource.com/sdk.git/+log/83c6b6124380..7b645442db0f

2025-09-08 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com
Version 3.10.0-182.0.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 aaclarke@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:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

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': '83c6b612438015f61b641fa2f7d8f128f85353a0',
+  'dart_revision': '7b645442db0f832e17269eff352dea0918f23a0b',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py