Remove legacy node parent detection (#12814)

ui/components/app/menu-droppo.js

@@ -39,10 +39,9 @@ export default class MenuDroppoComponent extends Component {
     if (
       this.props.isOpen &&
       target !== container &&
-      !isDescendant(this.container, event.target) &&
-      this.props.onClickOutside
+      !this.container.contains(event.target)
     ) {
-      this.props.onClickOutside(event);
+      this.props.onClickOutside?.(event);
     }
   };
 
@@ -117,15 +116,3 @@ export default class MenuDroppoComponent extends Component {
     );
   }
 }
-
-function isDescendant(parent, child) {
-  let node = child.parentNode;
-  while (node !== null) {
-    if (node === parent) {
-      return true;
-    }
-    node = node.parentNode;
-  }
-
-  return false;
-}