Every cycle or two the Nova project raises our min qemu and libvirt versions
and advertised what our next min version requirement will be.

https://docs.openstack.org/nova/latest/reference/libvirt-distro-support-matrix.html

We last did this in the wallaby release where we raised our min libvirt to 6.0.0 and min qemu to 4.2.0

or declared next min libvirt is 7.0.0 and qemu 5.2.0

we have deferred implementing that for 4 release now and are long overdue this change.

This epic tracks addressing this tech debt.