detchar create_cache falling back to datafind unexpectedly
This MDC event (https://gracedb.ligo.org/superevents/MS240416n/view/) has omegascans which fail in a way that is unexpected to me. The Sentry breadcrumbs show that datafind is queried, and returns a missing segments response (which is sensible, since this is queried <min after the time of the data, so the segments haven't been created yet)
but we should only be falling back to gwdatafind in create_cache (https://git.ligo.org/emfollow/gwcelery/-/blob/main/gwcelery/tasks/detchar.py?ref_type=heads#L45) if the data is not in the low latency cache, which it should be. I don't understand why this data isn't in the cache.