Preliminary PR for engine changes for Expanded/Collapsed Submenu button (#131359)

This PR is to skip some unit tests in order to merging an [engine
change](https://github.com/flutter/engine/pull/43983).

packages/flutter/test/widgets/custom_painter_test.dart

@@ -520,7 +520,7 @@ void _defineTests() {
     );
     expect(semantics, hasSemantics(expectedSemantics, ignoreRect: true, ignoreTransform: true));
     semantics.dispose();
-  });
+  }, skip: true); // https://github.com/flutter/flutter/issues/127617
 
   group('diffing', () {
     testWidgets('complains about duplicate keys', (WidgetTester tester) async {

packages/flutter/test/widgets/semantics_test.dart

@@ -706,7 +706,7 @@ void main() {
       ],
     );
     expect(semantics, hasSemantics(expectedSemantics, ignoreId: true));
-  });
+  }, skip: true); // https://github.com/flutter/flutter/issues/127617
 
   testWidgets('Actions can be replaced without triggering semantics update', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);