Revert "fix(ui)：keep destroy widgets out of the widget's active list (#19214)"

This reverts commit 64f4c38.

Author: star-e

cocos/ui/widget-manager.ts

@@ -204,7 +204,7 @@ function align (node: Node, widget: Widget): void {
 // TODO: type is hack, Change to the type actually used (Node or BaseNode) when BaseNode complete
 function visitNode (node: any): void {
     const widget = node.getComponent(Widget);
-    if (widget && widget.enabled && cclegacy.isValid(widget, true)) {
+    if (widget && widget.enabled) {
         if (DEV) {
             widget._validateTargetInDEV();
         }

cocos/ui/widget.ts

@@ -852,9 +852,6 @@ export class Widget extends Component {
     }
 
     public onDestroy (): void {
-        // `onDisable` is skipped when the component was never enabled by the scheduler
-        // (`IsOnEnableCalled` unset), so unregister here as well.
-        cclegacy._widgetManager?.remove(this);
         this._removeParentEvent();
     }