Cache::put should not resolve/reject the promise if the context is stopped
<rdar://problem/102607428>
<rdar://38103818>
Pull request: https://github.com/WebKit/WebKit/pull/6737
Committed 257083@main (fe7a1d0561c8): <https://commits.webkit.org/257083@main> Reviewed commits have been landed. Closing PR #6737 and removing active labels.