Cirrus: Allow FreeBSD 11.4 to fail
Cirrus: Allow FreeBSD 11.4 to fail

`latest` repo for 11.4 is missing the "rust" package, breaking the
build. It's fine, we can just wait it out.

newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat,der-lyse/newsboat,newsboat/newsboat,newsboat/newsboat