Re-import css/css-color-adjust WPT
<rdar://problem/100099445>
<rdar://problem/100099468>
Pull request: https://github.com/WebKit/WebKit/pull/4470
Committed 254641@main (e08b533e57f3): <https://commits.webkit.org/254641@main> Reviewed commits have been landed. Closing PR #4470 and removing active labels.