Roll Dart SDK from 8affa8a9de76 to 8c7f8aaa9c79 (1 revision) (#25069)

DEPS

@@ -35,7 +35,7 @@ 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': '8affa8a9de764041eb21a435af1ac16be59c55d3',
+  'dart_revision': '8c7f8aaa9c797da924a678ca61e60cbd990f6538',
 
   # 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: 8566b7e46097fad2dce19135550aeb46
+Signature: 4f0bcb7854f3a1099c1123fdb840d72a
 
 UNUSED LICENSES: