setup: allow centos up to version 9

setup: allow centos up to version 9

[0]: https://forum.proxmox.com/threads/centos-8-1-lxc-unsupported-centos-release.63530/

so that we handle all the point releases between 8-9

Signed-off-by: Oguz Bektas <o.bektas@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
(cherry picked from commit c823eb0a1b2b04bc7745bbac4819be9a9c96df51)
(cherry picked from commit 6566b196964dd8723eebf7c43181854b669f6e87)
[ Thomas: Squashed above two cherry-picks into one commit ]
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>