Define sane Oban Worker timeouts

lib/pleroma/workers/attachments_cleanup_worker.ex

lib/pleroma/workers/background_worker.ex

lib/pleroma/workers/backup_worker.ex

lib/pleroma/workers/mailer_worker.ex

lib/pleroma/workers/mute_expire_worker.ex

lib/pleroma/workers/poll_worker.ex

lib/pleroma/workers/publisher_worker.ex

lib/pleroma/workers/purge_expired_activity.ex

lib/pleroma/workers/purge_expired_filter.ex

lib/pleroma/workers/purge_expired_token.ex

lib/pleroma/workers/receiver_worker.ex

lib/pleroma/workers/remote_fetcher_worker.ex

lib/pleroma/workers/scheduled_activity_worker.ex

lib/pleroma/workers/transmogrifier_worker.ex

lib/pleroma/workers/web_pusher_worker.ex