Roll Dart SDK from c18e6d47bab0 to b9eedf5858f0 (1 revision) (#36250)

diff --git a/DEPS b/DEPS
index 5246456..5527860 100644
--- a/DEPS
+++ b/DEPS
@@ -43,7 +43,7 @@
   # 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': 'c18e6d47bab0433bf067c008eee93f8d3979e94a',
+  'dart_revision': 'b9eedf5858f022e03b8ec24eb8f548ed13fb8ba6',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py