This is actually a Debian bug and should be fixed there.

If cockpit requires systemd, is should declare that dependency.

If the dependency were present, amprolla would exclude cockpit from the Devuan
archives.

So I suggest you submit a bug to Debian's BTS asking for the explicit systemd
dependency to be added.

If we want/need cockpit to work in Devuan that is a whole new problem ;)

Thanks

Mark