[WebGPU] Index buffer can read outside the range of a vertex buffer
<rdar://problem/127672770>
Pull request: https://github.com/WebKit/WebKit/pull/28278
Committed 279182@main (e6d5e1a6604e): <https://commits.webkit.org/279182@main> Reviewed commits have been landed. Closing PR #28278 and removing active labels.