Remove all obsolete "// ignore:" (#27271)

packages/flutter_tools/lib/src/vmservice.dart

diff --git a/packages/flutter_tools/lib/src/vmservice.dart b/packages/flutter_tools/lib/src/vmservice.dart
index c733b52..2585c50 100644
--- a/packages/flutter_tools/lib/src/vmservice.dart
+++ b/packages/flutter_tools/lib/src/vmservice.dart
@@ -1384,7 +1384,7 @@
   Iterable<MapEntry<String, dynamic>> get entries => _map.entries;
   @override
   void updateAll(dynamic update(String key, dynamic value)) => _map.updateAll(update);
-  Map<RK, RV> retype<RK, RV>() => _map.cast<RK, RV>(); // ignore: annotate_overrides
+  Map<RK, RV> retype<RK, RV>() => _map.cast<RK, RV>();
   @override
   dynamic update(String key, dynamic update(dynamic value), {dynamic ifAbsent()}) => _map.update(key, update, ifAbsent: ifAbsent);
 }