Rebaseline / unskip some tests now that we supported nested dedicated workers.
Pull request: https://github.com/WebKit/WebKit/pull/4451
Committed 254629@main (f5b26fd2d682): <https://commits.webkit.org/254629@main> Reviewed commits have been landed. Closing PR #4451 and removing active labels.
<rdar://problem/100123587>