Fixes an error that will be thrown if `DebugRenderer2.destroyNode` is called with a node that has already been destroyed. The error happened, because we had a non-null assertion, even though the value can be null.
Note that this fix applies only to ViewEngine, because Ivy doesn't provide the `DebugRenderer2`. I decided to resolve it, because it fix is straightforward and this error has been showing up in our logs for a long time now, making actual errors harder to find.
PR Close#41565
aa0e54fe97