event_push_actions don't seem to be cleaned for some of my rooms

[matrixbot]

This issue has been migrated from #6060.

---

specifically, i have 19 entries in the EPA table for !zVpPeWAObqutioiNzB:jki.re despite being caught up on it. I thought every time i send a read receipt, my EPA entries from before the point I sent the read receipt should get cleaned out by _remove_old_push_actions_before_txn?

[moorglade]

It seems I've run into the same issue: rows with highlight = 1 are not deleted from event_push_actions, and so the table gets very large over time. I'm not sure if this is the expected behavior, or should those rows be deleted after some time.