Deprecate kubevirt/libvirt
Deprecate kubevirt/libvirt

Since the `v0.37.0` release of `kubevirt` this repo is no longer needed
in kubevirt.

Signed-off-by: Roman Mohr <6da0130c5aeef94e5bbaabadbf8017270be25c64@redhat.com>

kubevirt/libvirt