Reported upstream bu Ji Chen at https://github.com/openshift/installer/issues/4920 pkg/asset/installconfig/openstack/validation/cloudinfo.go has a typo that makes looking for the root cause of the error difficult: "could not find an available compute availability zone" should be replaced by "could not find an available volume availability zone".
Verified by code. The typo is resolved on installer repository (branch 4.8): https://github.com/openshift/installer/blob/release-4.8/pkg/asset/installconfig/openstack/validation/cloudinfo.go#L373
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Moderate: OpenShift Container Platform 4.8.2 bug fix and security update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2021:2438