tests: Fix domain-snapshot test to be run only when running on KVM hypervisor
tests: Fix domain-snapshot test to be run only when running on KVM hypervisor

Signed-off-by: Michal Novotny <8dce8af224790fd82cd80deb27431e4980a7ff31@redhat.com>

vtolstov/libvirt-php,tucksaun/libvirt-php,vtolstov/libvirt-php,libvirt/libvirt-php,tucksaun/libvirt-php,zippy2/libvirt-php,vtolstov/libvirt-php,tucksaun/libvirt-php,tucksaun/libvirt-php,zippy2/libvirt-php,libvirt/libvirt-php,zippy2/libvirt-php,vtolstov/libvirt-php,libvirt/libvirt-php