[WebGPU] Update WebGPU.h to upstream ToT
<rdar://problem/110156868>
Pull request: https://github.com/WebKit/WebKit/pull/14619
Committed 264836@main (219fc036fbe9): <https://commits.webkit.org/264836@main> Reviewed commits have been landed. Closing PR #14619 and removing active labels.
Committed 270527@main (185852691a2c): <https://commits.webkit.org/270527@main> Reviewed commits have been landed. Closing PR #19994 and removing active labels.