Please branch and build nunit in epel9. If you do not wish to maintain nunit in epel9, or do not think you will be able to do this in a timely manner, the EPEL Packagers SIG would be happy to be a co-maintainer of the package; please add the epel-packagers-sig group through https://src.fedoraproject.org/rpms/nunit/addgroup and grant it commit access, or collaborator access on epel* branches.
This is not needed for now.