Sunny confinement activities: upgrading datacenterlight.ch #FreeBSD images (dualstack and IPv6-only). Automating the process while at it.

Learnt a thing or two of #FreeBSD
releng team's work with that, could come in handy some day.

The whole thing is obviously Open Source, like most things at ungleich.ch:
https://code.ungleich.ch/ungleich-public/ungleich-tools/merge_requests/5