Roll Dart SDK from 20cca507d98b to 3d629d00a8d7 (2 revisions) (#38834)

https://dart.googlesource.com/sdk.git/+log/20cca507d98b..3d629d00a8d7

2023-01-13 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.0.0-121.0.dev
2023-01-12 dart-internal-merge@dart-ci-internal.iam.gserviceaccount.com Version 3.0.0-120.0.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 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 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
diff --git a/DEPS b/DEPS
index 2ab5059..13ddeeb 100644
--- a/DEPS
+++ b/DEPS
@@ -48,7 +48,7 @@
   # 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': '20cca507d98b2df9ef1942c6396f7d33a8a3c6e4',
+  'dart_revision': '3d629d00a8d7b1469c63d994181df19bcee5a299',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
diff --git a/ci/licenses_golden/licenses_third_party b/ci/licenses_golden/licenses_third_party
index 259b0b2..41d17ba 100644
--- a/ci/licenses_golden/licenses_third_party
+++ b/ci/licenses_golden/licenses_third_party
@@ -1,4 +1,4 @@
-Signature: 6810c906925365d689dcb832f7e8c7a9
+Signature: 77f9bd9b1689036bfc5ee73f17f9d033
 
 ====================================================================================================
 LIBRARY: angle