Cannot set `os_distro` to `rocky`

[mbuechse]

The following values are permissible according to the OpenStack docs:

arch - Arch Linux. Do not use archlinux or org.archlinux.
centos - Community Enterprise Operating System. Do not use org.centos or CentOS.
debian - Debian. Do not use Debian or `org.debian.
fedora - Fedora. Do not use Fedora, org.fedora, or org.fedoraproject.
freebsd - FreeBSD. Do not use org.freebsd, freeBSD, or FreeBSD.
gentoo - Gentoo Linux. Do not use Gentoo or org.gentoo.
mandrake - Mandrakelinux (MandrakeSoft) distribution. Do not use mandrakelinux or MandrakeLinux.
mandriva - Mandriva Linux. Do not use mandrivalinux.
mes - Mandriva Enterprise Server. Do not use mandrivaent or mandrivaES.
msdos - Microsoft Disc Operating System. Do not use ms-dos.
netbsd - NetBSD. Do not use NetBSD or org.netbsd.
netware - Novell NetWare. Do not use novell or NetWare.
openbsd - OpenBSD. Do not use OpenBSD or org.openbsd.
opensolaris - OpenSolaris. Do not use OpenSolaris or org.opensolaris.
opensuse - openSUSE. Do not use suse, SuSE, or ` org.opensuse`.
rocky - Rocky Linux. Do not use Rocky or rockylinux.
rhel - Red Hat Enterprise Linux. Do not use redhat, RedHat, or com.redhat.
sled - SUSE Linux Enterprise Desktop. Do not use com.suse.
ubuntu - Ubuntu. Do not use Ubuntu, com.ubuntu, org.ubuntu, or canonical.
windows - Microsoft Windows. Do not use com.microsoft.server or windoze.

The schema permits

enum('arch', 'centos', 'cirros', 'clearlinux', 'debian', 'fedora', 'freebsd', 'opensuse', 'rhel', 'talos', 'ubuntu', 'windows')

which is both missing values (such as rocky) and listing extraneous ones (such as clearlinux or talos).

I suggest changing the schema to match the docs, and to add the switch I proposed in #1097.