Roll Dart SDK from ef4160e to 7d43846 (1 revision) (#31587)

Author: skia-flutter-autoroll

DEPS

@@ -39,7 +39,7 @@ vars = {
   # 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': 'ef4160e0de3185b1899349f65e709c40f0ba53be',
+  'dart_revision': '7d43846b42794c8550e947ddd1eb34bbb23663fc',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py