[WebGPU] Render / compute commands should be no-ops when the command buffer will be discarded
radar://128202440
Pull request: https://github.com/WebKit/WebKit/pull/28689
Committed 279034@main (1623111a075f): <https://commits.webkit.org/279034@main> Reviewed commits have been landed. Closing PR #28689 and removing active labels.