refactor clear (#26625)

src/core/Object3D.js

@@ -392,20 +392,7 @@ class Object3D extends EventDispatcher {
 
 	clear() {
 
-		for ( let i = 0; i < this.children.length; i ++ ) {
-
-			const object = this.children[ i ];
-
-			object.parent = null;
-
-			object.dispatchEvent( _removedEvent );
-
-		}
-
-		this.children.length = 0;
-
-		return this;
-
+		return this.remove( ... this.children );
 
 	}