InteractionRegions: should not look for link ancestors if a button ancestor has been found
<rdar://problem/107958544>
Pull request: https://github.com/WebKit/WebKit/pull/13816
Committed 264041@main (9217f7af3356): <https://commits.webkit.org/264041@main> Reviewed commits have been landed. Closing PR #13816 and removing active labels.