Please branch and build dbus-c++ in epel9. If you do not wish to maintain dbus-c++ 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/dbus-c++/addgroup and grant it commit access, or collaborator access on epel* branches. I would also be happy to be a co-maintainer (FAS: jonathanspw). I can be the primary contact for EPEL (FAS: jonathanspw).
This bug appears to have been reported against 'rawhide' during the Fedora Linux 39 development cycle. Changing version to 39.