tests: qemuxml: Purge prehistoric machine type 'pc-0.13' from "latest" tests

tests: qemuxml: Purge prehistoric machine type 'pc-0.13' from "latest" tests

Remove the old machine type which will be dropped in the upcomming
qemu-5.0 release from tests used against the most recent capabilities
data.

None of the modified tests really cares about the actual machine type.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>