This will be used to store the missedmessage events received
during the waiting time for email notifications (which is currently
2 minutes, hardcoded).
The change in `test_retention` is because we've set `on_delete=CASCADE`
for the message field this table.
The new query is like so:
```
DELETE FROM "zerver_missedmessageemailentry"
WHERE "zerver_missedmessageemailentry"."message_id" IN (
1545, 1546, 1547, 1548, 1549, 1550, 1551, 1552, 1553
)
```
Abhijeet Prasad Bodas