[WebGPU] Dynamics offsets is in uint's but code assumes it is in bytes
<rdar://problem/118971735>
Pull request: https://github.com/WebKit/WebKit/pull/21094
Committed 271351@main (2714034088ac): <https://commits.webkit.org/271351@main> Reviewed commits have been landed. Closing PR #21094 and removing active labels.