[Regr:6.6.0->6.6.1] PyQt6 app reports The cached device pixel ratio value was stale on window expose

SUMMARY

PyQt6 programs report "The cached device pixel ratio value was stale on window expose. Please file a QTBUG which explains how to reproduce." when exiting.

The same code running under Fedora 39 KDE with Qt 6.6.0 does not show the error.

STEPS TO REPRODUCE
1. Run the attached qtbug.py script from a terminal.
2. Click on [X] to close the window
3. Error message shown in terminal.

OBSERVED RESULT

$ py3 qtbug.py
The cached device pixel ratio value was stale on window expose. Please file a QTBUG which explains how to reproduce.

EXPECTED RESULT

No error printed.

SOFTWARE/OS VERSIONS
Windows:
macOS:
Linux/KDE Plasma: Fedora rawhide: KDE plasma 6.0 beta 2
(available in About System)
KDE Plasma Version: 5.91.0
KDE Frameworks Version: 5.247.0
Qt Version: 6.6.1
PyQt6 Version: python3-pyqt6-6.6.1-1.fc40.x86_64
ADDITIONAL INFORMATION