An error was introduced in [0], it added an incorrect dependency on
genisoimage for nova, and kept a valid dependency on xorriso in n-cpu.
It breaks centos 10 deployments, the expected behavior is to use xorriso
on modern rhel/centos.
[0] https://review.opendev.org/c/openstack/devstack/+/963799
Change-Id: I0057f934c453ded198f8b5e58f4924260a3d2508
Signed-off-by: Gregory Thiemonge <gthiemon@redhat.com>