conda/Linux: Bad PySide6 runpath causes dependency problem

The following steps reproduce the problem:

$ conda create -n krbfail python cmake

$ conda activate krbfail

$ pip install PySide6

$ python -c "from PySide6 import QtCore"
 
Here are our findings from this:

• conda install cmake installs krb5 as a dependency (libs go into conda environment)
• pip install PySide6 installs a QtCore.abi3.so with a RUNPATH value that IMO is broken.
• from PySide6 import QtCore only looks for libgssapi_krb5.so in the Qt/lib folder because of its broken RUNPATH (it should have a relative path to play well with other conda packages).
• It does not find that library there, and so falls back on the system version of the library.
• libgssapi_krb5.so looks for libkrb5.so using the python RUNPATH, which leads it to the conda-forge one.
• The compiler options used for the system krb5 and the conda-forge krb5 do not match; python is now using one from each.
• Undefined symbol ensues.