Roll Dart SDK from fcafd43f2cf7 to b9c5118c73fd (11 revisions) (#20301)

DEPS

@@ -34,7 +34,7 @@ vars = {
   # Dart is: https://github.com/dart-lang/sdk/blob/master/DEPS.
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': 'fcafd43f2cf7e2981441c47b25cff6b0c73ec610',
+  'dart_revision': 'b9c5118c73fda9a2e43e204ae52e375874bff9f0',
 
   # 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

-Signature: c10dfac4542d95f3e5e9ce60155ee4ff
+Signature: a70112ca278316b38ab1368cc0e8cab0
 
 UNUSED LICENSES: