Roll Dart SDK from a88ed8cafd27 to a6e43b0b9e0c (1 revision) (#46674)

https://dart.googlesource.com/sdk.git/+log/a88ed8cafd27..a6e43b0b9e0c

2023-10-09 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.3.0-2.0.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

Author: skia-flutter-autoroll

DEPS

@@ -57,7 +57,7 @@ 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': 'a88ed8cafd27d769e10fe4d864821d3c8466d713',
+  'dart_revision': 'a6e43b0b9e0cd6c16dff5b507e50ee6cd286c729',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -472,7 +472,7 @@ deps = {
    Var('dart_git') + '/string_scanner.git@9c525f78fbc4189ee4dc3171a5c79e925b58f58b',
 
   'src/third_party/dart/third_party/pkg/tar':
-   Var('dart_git') + '/external/github.com/simolus3/tar.git@3c68cba8e51c569428222b9185469249206172c6',
+   Var('dart_git') + '/external/github.com/simolus3/tar.git@748f6e680206752cc8e7a3c30af78a86da9830bd',
 
   'src/third_party/dart/third_party/pkg/term_glyph':
    Var('dart_git') + '/term_glyph.git@cff80de129b2e69c11e3a9d7c6ea0447fc37865b',

ci/licenses_golden/licenses_dart

@@ -1,4 +1,4 @@
-Signature: 927afe41ea1670682957ff1fe345c21d
+Signature: 116a50d0facb820efdab648f654d3c41
 
 ====================================================================================================
 LIBRARY: dart