It's not universally accepted here and a `when` crept in that can be
bypassed entirely using rather clean baseline language constructs, so
why bother at this point.
Compare: https://github.com/ppy/osu/pull/24548.
I don't have a reproduction scenario (judging from the stack trace
of the crash it's likely to be nigh-impossible to concoct a reliable
one), but there is some circumstantial evidence that this might help,
namely that that previous fix above worked, and the pathway that's
failing here is similarly async to the one that pull fixed. So I'm just
gonna start with that and hope that it does the job.