- The action tables can become very large as it's a dumpster for every
action that an user does on an repository.
- The following query: `DELETE FROM action WHERE comment_id IN (SELECT id FROM comment WHERE
issue_id=?)` is not using indexes for `comment_id` and is instead using
an full table scan by MariaDB.
- Rewriting the query to use an JOIN will allow MariaDB to use the
index.
- More information: https://codeberg.org/Codeberg-Infrastructure/techstack-support/issues/9
- Backport https://codeberg.org/forgejo/forgejo/pulls/1154
