PyQt v6.12.0 Wheels Available for Testing

[Phil Thompson]

The PyQt v6.12.0 wheels are available from the local pypi server for 
testing (as are the corresponding Qt wheels).

There are some caveats...

- The QtCore module includes an embedded qt.conf file which enables 
QLibraryInfo to return the correct paths. However this no longer seems 
to work on macOS. I have implemented a temporary workaround so that 
plugins can be found.

- The QtPdf and QtPdfWidgets modules have been moved from PyQt6 to 
PyQt6-WebEngine. As Qt WebEngine v6.140 (which will be the next version) 
has yet to be released there are not yet any PyQt6-WebEngine wheels.

- There will be a separate PyQt6-CanvasPainter package - it isn't quite 
ready yet.

I will time the final release to be just after the release of Python 
v3.15.

Phil