I notice `pg_dump` is still complaining about the collation:
```
WARNING: database "mastodon_production" has a collation version mismatch
DETAIL: The database was created using collation version 2.36, but the operating system provides version 2.41.
HINT: Rebuild all objects in this database that use the default collation and run ALTER DATABASE mastodon_production REFRESH COLLATION VERSION, or build PostgreSQL with the right library version.
```
… but it seems to be running okay. I don't feel like doing a `DROP DATABASE` and restore at this time to rebuild the objects, unless there's some simpler way to do a rebuild.
Anyway, the build is started, we should be back soonish.