We changed how we serialize the `transition` shorthand property in bug 266234 / 272513@main and we should do the same for `animation`.
Pull request: https://github.com/WebKit/WebKit/pull/22367
Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/43844
Committed 272629@main (3b19eaa5f921): <https://commits.webkit.org/272629@main> Reviewed commits have been landed. Closing PR #22367 and removing active labels.
<rdar://problem/120439368>