backend: Add cron to supervisord monitored processes
requested to merge adalessandro/open-build-service:wip/adalessandro/aptly-cleanup-cron into collabora/staging
Task https://phabricator.apertis.org/T8672
Cron will be used to run periodic jobs on the backend. Let's add this to the processed launched and monitored by supervisor.
Such cron functionality is required by aptly, which has been now integrated to OBS. A few related scripts need to be run on the backend to perform maintenance tasks.