pyqtgraph: Issues in environments including both PyQt5 and PySide

[willend]

An issue with the pyqtgraph plotters on Windows systems may prevent to open a subplot, see report sent to mcstas-users:
https://mailman2.mcstas.org/pipermail/mcstas-users/2024q4/001542.html

The issue seems related to presence of pyside6 in the otherwise pyqt5 oriented environment and a workaround is to:

1. Take “ownership” (i.e. give yourself all levels of filesystem access) of c:\mcstas-3.5.1\miniconda3
2. Start an “environment terminal”
3. mamba uninstall pyside6

(Related to previous issue #1582)

[willend]

The issue persists. Let us keep open until a long term solution (i.e. full port to PyQt6/PySide6) is found.