Cleanup from previous PR

https://github.com/element-hq/synapse/pull/19268/changes#r2614217300 wasn't applied and the migration had copy/paste artifacts.

PR: https://github.com/element-hq/synapse/pull/19268

changelog.d/19268.feature

@@ -1 +1 @@
-Add an admin API for retrieving a paginated list of quarantined media.
+Add a ["Listing all quarantined media" Admin API](https://element-hq.github.io/synapse/latest/admin_api/media_admin_api.html#listing-all-quarantined-media) for retrieving a paginated list of quarantined media.

synapse/storage/schema/main/delta/93/04_add_quarantined_ts_to_media.sql

@@ -11,12 +11,6 @@
 -- See the GNU Affero General Public License for more details:
 -- <https://www.gnu.org/licenses/agpl-3.0.html>.
 
--- Add a timestamp for when the sliding sync connection position was last used,
--- only updated with a small granularity.
---
--- This should be NOT NULL, but we need to consider existing rows. In future we
--- may want to either backfill this or delete all rows with a NULL value (and
--- then make it NOT NULL).
 ALTER TABLE local_media_repository ADD COLUMN quarantined_ts BIGINT;
 ALTER TABLE remote_media_cache ADD COLUMN quarantined_ts BIGINT;