kojivmd: cleanup VMs with UNDEFINE_NVRAM
    
    Newer virtual machines may use nvram, and libvirt needs a special flag
    to clean these up. Prior to this change (with libvirt-8.0.0-8.1.el9_0):
    
      File "/usr/sbin/kojivmd", line 1072, in cleanupVM
        vm.undefine()
      File "/usr/lib64/python3.9/site-packages/libvirt.py", line 3178, in undefine
        raise libvirtError('virDomainUndefine() failed')
      libvirt.libvirtError: Requested operation is not valid: cannot undefine
        domain with nvram
    
    RHEL 7 first introduced the libvirt.VIR_DOMAIN_UNDEFINE_NVRAM flag in
    libvirt-python-1.2.8-7.el7 (rhbz#1144284)