Sorry, I'm afraid you are out of luck.
The ident command is part of the Revision Control System, aka RCS.
RCS used to be available in RHEL/Centos, but was dropped in RHEL 8 according to the RHEL 8.0.0 release notes:
Note that the Concurrent Versions System (CVS) and Revision Control
System (RCS), available in RHEL 7, are not distributed with RHEL 8.
As far as I can see, there is no other RHEL package that contains ident either - not suprising, as it is probably only useful together with RCS.
You can probably install it manually some way, either by using an older or third-party package (but be careful about compatibility), or by building it yourself.
However, in the long run you should probably consider replacing your use of ident and RCS - it is ancient software, and will probably become more and more difficult to support in futures (as you can see by this problem).
Consider asking a new question about how to replace your use of RCS :-).