libblkio is already in c9s and is being added to RHEL 9.3 (so we can't branch it for EPEL 9) but libblkio-devel is being filtered out. Per the unshipped packages policy, I'd like to request libblkio-devel to be added to CRB so it can be used to unblock building packages that depend on it in EPEL 9 (notably qemu, which is something I'm working on as part of the CentOS Hyperscale SIG).