feat: remove stale ONLINE_PRESENCE contact keys in redis (#9558)

50% of Redis memory size comes from ONLINE_PRESENCE keys. This PR adds a
periodic job to remove stale keys from all accounts.

config/schedule.yml

@@ -26,3 +26,10 @@ remove_stale_contact_inboxes_job.rb:
   cron: '30 22 * * *'
   class: 'Internal::RemoveStaleContactInboxesJob'
   queue: scheduled_jobs
+
+# executed daily at 2230 UTC
+# which is our lowest traffic time
+remove_stale_redis_keys_job.rb:
+  cron: '30 22 * * *'
+  class: 'Internal::RemoveStaleRedisKeysJob'
+  queue: scheduled_jobs