Refactor LFS GC functions

- Remove options that currently aren't set
on `GarbageCollectLFSMetaObjectsOptions` and
`IterateLFSMetaObjectsForRepoOptions`.
- Simplify `IterateRepositoryIDsWithLFSMetaObjects` and
`IterateLFSMetaObjectsForRepo`.
- `IterateLFSMetaObjectsForRepo` was previously able to get in a
loop (`gc-lfs` doctor check was able to reproduce this) because the code
expected that the records would be updated to not match the SQL query,
but that wasn't the case. Simply enforce that only records higher than
the latest `id` from the previous iteration are allowed.
- For `gc-lfs` doctor check this was because `UpdatedLessRecentlyThan`
option was not set, which caused that records just marked as active in
the iteration weren't being filtered.
- Add unit tests
- Most likely a regression from 2cc3a6381c.
- The bug with `gc-lfs` was found on Codeberg.

services/doctor/lfs.go

@@ -44,6 +44,7 @@ func garbageCollectLFSCheck(ctx context.Context, logger log.Logger, autofix bool
 		OlderThan: time.Now().Add(-24 * time.Hour * 7),
 		// We don't set the UpdatedLessRecentlyThan because we want to do a full GC
 	}); err != nil {
+		logger.Error("Couldn't garabage collect LFS objects: %v", err)
 		return err
 	}