Update Flutter version in github action.

Author: timbotimbo

.github/workflows/main.yaml

@@ -11,7 +11,7 @@ jobs:
 
       - uses: subosito/flutter-action@v2
         with:
-          flutter-version: '3.3.0'
+          flutter-version: '3.24.5'
           channel: 'stable'
 
       - name: Clean Dependencies
@@ -21,7 +21,7 @@ jobs:
         run: flutter packages get
 
       - name: Format
-        run: flutter format --set-exit-if-changed lib test
+        run: dart format --set-exit-if-changed lib test
 
       - name: Analyze
         run: flutter analyze lib test

test/fake_unity_widget_controllers.dart

@@ -7,7 +7,8 @@ class FakePlatformUnityWidget {
   FakePlatformUnityWidget(int id, Map<dynamic, dynamic> params)
       : channel = MethodChannel(
             'plugin.xraph.com/unity_view_$id', const StandardMethodCodec()) {
-    channel.setMockMethodCallHandler(onMethodCall);
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(channel, onMethodCall);
   }
 
   MethodChannel channel;

test/flutter_unity_widget_test.dart

@@ -16,16 +16,18 @@ Future<void> main() async {
   TestWidgetsFlutterBinding.ensureInitialized();
 
   setUpAll(() {
-    SystemChannels.platform_views.setMockMethodCallHandler(
-        fakePlatformViewsController.fakePlatformViewsMethodHandler);
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(SystemChannels.platform_views,
+            fakePlatformViewsController.fakePlatformViewsMethodHandler);
   });
 
   setUp(() {
     fakePlatformViewsController.reset();
   });
 
   tearDown(() {
-    channel.setMockMethodCallHandler(null);
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(channel, null);
   });
 
   testWidgets('Unity widget ready', (WidgetTester tester) async {