The changes described below drop a table and a column from an existing table, so in the unlikely event that any mirrors reference these schema objects, they should stop.  (Note that the release_coverart table is not replicated.)

Drop the release_coverart table

This mostly stores stale Amazon cover art from when we used to calculate those.  (The code for fetching these has been broken for years.)  But as decided for MBS-12157, we are dropping Amazon cover art support.  The only other non-Amazon URL I saw in this table was a single archive.org URL – no other previously-whitelisted artwork site.

Drop the release_meta.amazon_store column

This column is completely empty in production and unused!