[WebGPU] Queue::onSubmittedWorkDone may crash if device is destructed
<rdar://problem/122020549>
radar://122010484
Pull request: https://github.com/WebKit/WebKit/pull/23593
Committed 273870@main (d08e8b03938a): <https://commits.webkit.org/273870@main> Reviewed commits have been landed. Closing PR #23593 and removing active labels.