In case anyone is interested, a PR was submitted by someone to the zm-build repo of Zimbra for Rocky support. I have my own set of scripts of which I prepared that assist in making the build process much easier, and have subsequently built a version of Zimbra 9.x that works on Rocky Linux. This is because my build scripts are patching the code with the PR that is waiting to be accepted. Once Zimbra accept the PR, then I won’t need to do that anymore in my build scripts.
My Zimbra build scripts can be found here if you want to build yourself: GitHub - ianw1974/zimbra-build-scripts: Zimbra Build Helper Script - makes it easier to build Zimbra
If you want to just download and install Zimbra on Rocky, you can get it from here: GitHub - ianw1974/zimbra-builds: Zimbra Builds created from my Zimbra Build Helper script