Reverts "Roll Dart SDK from 6219f11bf0fb to b3d3b381fd7b (1 revision)" (flutter/engine#48011)

Reverts flutter/engine#48006
Initiated by: zanderso
This change reverts the following previous change:
Original Description:

https://dart.googlesource.com/sdk.git/+log/6219f11bf0fb..b3d3b381fd7b

2023-11-14 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.3.0-128.0.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 bdero@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://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

DEPS

@@ -59,7 +59,7 @@ 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': 'b3d3b381fd7b1108248d4860c1c25350b9f5c962',
+  'dart_revision': '6219f11bf0fba6f87b81c027e677f8371b6896b8',
 
   # 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/ci/licenses_golden/licenses_dart

@@ -1,4 +1,4 @@
-Signature: fcdeadf333c7490a6eb3c788c8aec866
+Signature: 488c06d955ffe4b82a008e539c0a3d75
 
 ====================================================================================================
 LIBRARY: dart