Revert "[keyserver] cron job to sync reserved usernames"

This reverts commit 9a75d88.

keyserver/src/cron/cron.js

@@ -6,7 +6,6 @@ import schedule from 'node-schedule';
 import { backupDB } from './backups.js';
 import { createDailyUpdatesThread } from './daily-updates.js';
 import { updateAndReloadGeoipDB } from './update-geoip-db.js';
-import { updateIdentityReservedUsernames } from './update-identity-reserved-usernames.js';
 import { deleteOrphanedActivity } from '../deleters/activity-deleters.js';
 import { deleteExpiredCookies } from '../deleters/cookie-deleters.js';
 import { deleteOrphanedDays } from '../deleters/day-deleters.js';
@@ -93,20 +92,7 @@ if (cluster.isMaster) {
       }
     },
   );
-  schedule.scheduleJob(
-    '0 5 * * *', // every day at 5:00 AM in the keyserver's timezone
-    async () => {
-      try {
-        await updateIdentityReservedUsernames();
-      } catch (e) {
-        console.warn(
-          'encountered error while trying to update reserved usernames on ' +
-            'identity service',
-          e,
-        );
-      }
-    },
-  );
+
   schedule.scheduleJob(
     '0 0 * * *', // every day at midnight in the keyserver's timezone
     async () => {