it seems that https://github.com/mhagger/cvs2svn is the semi-official new home of a backup of the old tigris website which was shutdown. I’m not sure if it will work though with its dependency on Python 2 (deprecated).
Maybe you can make cvs2svn work, this worked reliably in the past decade to migrate old projects to Git platforms. An idea would be to create a custom Docker image which provides the Python 2 cvs2svn installation, and you just run the migration on your RHEL8 host inside a container.