investigate/set up GCZ cvmfs cache cleaning

[martenson]

What could be useful is this part. I used it before on usegalaxy.cz because there is limited space on the drive and cvmfs cache somehow used to exceed the quota very often above the pre-set quota limit. Not sure why.

Originally posted by @martindemko in #95 (comment)

#    - name: Setup CVMFS cache cleaning
#      ansible.builtin.cron:
#        name: "CVMFS cache cleaning"
#        user: root
#        minute: "0"
#        hour: "*/12"
#        job: "cvmfs_talk -i singularity.galaxyproject.org cleanup {{ cvmfs_quota_limit }}"