ci: fix docker fedora PythonQt install
The PythonQtPlugin test was failing as it couldn't find libPythonQt.so https://open.cdash.org/test/943850706, it is looking the lib in /lib64/
and libPythonQt.so is currently installed in /lib/
Related to !6118 (merged) and fixes changes from !6123 (merged)
Edited by Timothée Couble