Roll Dart SDK from 9d3b9460df97 to a474d0e9093b (1 revision) (#34644)

diff --git a/DEPS b/DEPS
index ce991b5..351ba81 100644
--- a/DEPS
+++ b/DEPS
@@ -35,7 +35,7 @@
   # 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': '9d3b9460df974bb49c42ecd132a7de0cab498209',
+  'dart_revision': 'a474d0e9093bb4910ec0790485e2a58f55334b0e',
 
   # 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 92791b7..f2a2994 100644
--- a/ci/licenses_golden/licenses_third_party
+++ b/ci/licenses_golden/licenses_third_party
@@ -1,4 +1,4 @@
-Signature: 847520e0db2f9e417c9d1430ddbd88b0
+Signature: 65e74b901bfc9dff4c387afaed93bd8b
 
 UNUSED LICENSES: