mgr/cephadm: suppress CEPHADM_FAILED_DAEMON for services being removed
When a service is deleted, a daemon belonging to it may transiently
enter a failed state before orphan cleanup removes it. This happens
when there is a race between dependency-changed REDEPLOY and a
service removal going on paralelly.
Skip daemons in update_failed_daemon_health_check whose service is
already in spec_deleted.