Otherwise attachments have a high chance to disappear with akkoma-fe’s
“delete & redraft” feature when cleanup is enabled in the backend. Since
we don't know whether a deletion was intended to be part of a redraft
process or even if whether the redraft was abandoned we still have to
delete attachments eventually.
A thirty minute delay should provide sufficient time for redrafting.
Fixes: #775
The cleanup attachment worker was run for every deleted post,
even if it’s a remote post whose attachments we don't even store.
This was especially bad due to attachment cleanup involving a
particularly heavy query wasting a bunch of database perf for nil.
This was uncovered by comparing statistics from
#784 and
#765 (comment)
