useMovingAnimation: Clear translate3d rule when animation is finished (…

…#56410)

* useMovingAnimation: Clear translate3d rule when animation is finished

* Add inline comment for clarity

packages/block-editor/src/components/use-moving-animation/index.js

@@ -129,7 +129,7 @@ function useMovingAnimation( {
 		const finishedMoving = x === 0 && y === 0;
 		ref.current.style.transformOrigin = 'center center';
 		ref.current.style.transform = finishedMoving
-			? undefined
+			? null // Set to `null` to explicitly remove the transform.
 			: `translate3d(${ x }px,${ y }px,0)`;
 		ref.current.style.zIndex = isSelected ? '1' : '';