WebsiteDataStoreClient::notifyBackgroundFetchChange should exit early if its delegate does not have the corresponding selector
<rdar://problem/106285707>
Pull request: https://github.com/WebKit/WebKit/pull/11105
Committed 261365@main (7442d8810faf): <https://commits.webkit.org/261365@main> Reviewed commits have been landed. Closing PR #11105 and removing active labels.