Description of the change

I would like to use k8s' CronJob resources to run nextcloud's cronjob tasks instead of having them executed by the cron container.

Benefits

• easier to add new cronjobs (e.g. for certain apps like image preview pre generation or duplicate detection)
• more/easier insight into failed cronjobs through cluster monitoring
• separate resource limits when multiple cronjobs are configured

Possible drawbacks

I'm not entirely clear on how this might interact with nextcloud during upgrades, but I don't think it changes much compared to the status quo.

Additional information