Apple M1 install LLVM version 9

CONTEXT: I am trying to install a plugin within QGIS. The plugin requires many python packages which I am installing via pip3. One of the packages being LLVMLITE at version 0.33.0. My MacOS is Ventura

I get an error saying:

RuntimeError: Building llvmlite requires LLVM 9.0.x, got '11.1.0'. Be sure to set LLVM_CONFIG to the right executable path.
  Read the documentation at http://llvmlite.pydata.org/ for more information about building llvmlite.

It is asking for LLVM version 9.

I have been successful in getting LLVM version 11 via brew. I have tried getting version 9 but I get an error:

llvm@9: The x86_64 architecture is required for this software.
Error: llvm@9: An unsatisfied requirement failed this build.

QUESTION:

Is there in anyway I can move forward?

Thank you in advance.

Solution

I followed the advice by @JeremeyP. I could install llvm version 9 via macports. Following the install you have to change the pathing to the installation path made with macports.

Already using the QGIS tool I can see that there are implications, namely that python package versions being installed are of deprecated ones, i.e.: Import Error: No module named pkg_resources

You have to really need to spend sometime on the package dependencies.