vm-configurator: Use USB3 for supported OSes
This requires changes yet to land in a libvirt-glib release.
https://gitlab.com/libvirt/libvirt-glib/-/commit/2f00708ca612eaf0f49e3f17e2d9a223b69b461f and https://gitlab.com/libvirt/libvirt-glib/-/merge_requests/5