Remove unnecessary question marks (#77719)

packages/flutter/lib/src/animation/tween.dart

@@ -259,7 +259,7 @@ class Tween<T extends dynamic> extends Animatable<T> {
     assert(() {
       // Assertions that attempt to catch common cases of tweening types
       // that do not conform to the Tween requirements.
-      dynamic? result;
+      dynamic result;
       try {
         result = begin + (end - begin) * t;
         result as T;

packages/flutter/test/widgets/widget_inspector_test.dart

@@ -1536,7 +1536,7 @@ class _TestWidgetInspectorService extends TestWidgetInspectorService {
       service.disposeAllGroups();
       await service.testExtension('setPubRootDirectories', <String, String>{});
       service.setSelection(elementA, 'my-group');
-      final Map<String, dynamic?> jsonA = (await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}))! as Map<String, dynamic?>;
+      final Map<String, dynamic> jsonA = (await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}))! as Map<String, dynamic>;
 
       await service.testExtension('setPubRootDirectories', <String, String>{});
       Map<String, Object?> rootJson = (await service.testExtension('getRootWidgetSummaryTree', <String, String>{'objectGroup': group}))! as Map<String, Object?>;