Roll Dart SDK from 551915bf6ebe to 51d6128b190e (1 revision) (#43581)

https://dart.googlesource.com/sdk.git/+log/551915bf6ebe..51d6128b190e

2023-07-11 [email protected] Version 3.1.0-298.0.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 [email protected],[email protected] 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

Author: skia-flutter-autoroll

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': '551915bf6ebefc15d62be15b05a956722f0972a4',
+  'dart_revision': '51d6128b190eef58fc16e160937b069631776cce',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py

ci/licenses_golden/licenses_third_party

@@ -1,4 +1,4 @@
-Signature: f65f216a8b9df056ba70e862eca12ba4
+Signature: 1bfb48b357ab2192e8a2dd0b14c474f6
 
 ====================================================================================================
 LIBRARY: angle