Do not try to create upstream to backed out landing and downstream syncs #2079
Description
Recently we had the case of the landing being backed out from autoland: https://bugzilla.mozilla.org/show_bug.cgi?id=1863685#c18, and the bot tried to create an upstream sync: https://bugzilla.mozilla.org/show_bug.cgi?id=1863685#c17. The same happened for one downstream sync from this landing: https://bugzilla.mozilla.org/show_bug.cgi?id=1861850#c6. We should make sure that it happens only to changes introduced in gecko repo.