The physical hosts no longer need k3s or KubeVirt: aquamarine runs
natively, the k3s-test masters run as microVMs and kana/ruby under
libvirt. So drop the host cluster and split the shared parts out of the
KubeVirt host module:
- lib/genVmHostModule.nix: the host bits the VMs still need (br0 + the
physical NIC as a bridge port, KVM, sysctls, earlyoom, libvirt,
journald, stateVersion)
- the three hosts use it and drop genK3sServerModule; also drop the
longhorn workarounds (openiscsi + the /usr/local/bin tmpfile) and the
virtctl package
- remove lib/genKubeVirtHostModule.nix