Dispose widgets to stop leaks. (#108193)

Author: polina-c

packages/flutter/lib/src/material/ink_well.dart

@@ -847,6 +847,7 @@ class _InkResponseState extends State<_InkResponseStateWidget>
   void dispose() {
     FocusManager.instance.removeHighlightModeListener(handleFocusHighlightModeChange);
     statesController.removeListener(handleStatesControllerChange);
+    internalStatesController?.dispose();
     super.dispose();
   }
 

packages/flutter/lib/src/widgets/scroll_position.dart

@@ -976,6 +976,7 @@ abstract class ScrollPosition extends ViewportOffset with ScrollMetrics {
   void dispose() {
     activity?.dispose(); // it will be null if it got absorbed by another ScrollPosition
     _activity = null;
+    isScrollingNotifier.dispose();
     super.dispose();
   }