[openstack-helm][loci] Retire Centos based images

Hi team, We have a bunch of Centos related stuff in the Loci repo. However we've not been building and testing centos based images for quite some time. Is anybody still interested in having/maintaining this stuff? I am talking about [1] - [5]. [1] https://opendev.org/openstack/loci/src/branch/master/dockerfiles/centos [2] https://opendev.org/openstack/loci/src/branch/master/scripts/install.sh#L37-... [3] https://opendev.org/openstack/loci/src/branch/master/scripts/collect_info.sh... [4] https://opendev.org/openstack/loci/src/branch/master/scripts/install_package... [5] https://opendev.org/openstack/loci/src/branch/master/scripts/cleanup.sh#L14-... -- Best regards, Kozhukalov Vladimir