Add system-sb-certs for RHEL-9
Copy the RHEL-9 signing requirement over to ARK. This change is wrapped with "{?rhel} && !{?eln}" to allow Fedora and ELN to continue using their signing technology.
The system-sb-certs is just a metapackage for either rhel-sb-certs or centos-sb-certs, depending on what is installed on your system.
Tested by building under koji eln successfully.
Signed-off-by: Don Zickus dzickus@redhat.com