containers: Specify COPR chroot explicitly (#1627)
    
    A recent change to DNF COPR plugin [1] makes 'epel-9' the default chroot

    used for CentOS Stream 9. Let's specify the 'centos-stream-9' chroot

    name that we use in oVirt's COPR explictly.

    

    [1] https://github.com/rpm-software-management/dnf-plugins-core/pull/459

    

    Signed-off-by: Marcin Sobczyk <msobczyk@redhat.com>

    

    Signed-off-by: Marcin Sobczyk <msobczyk@redhat.com>