PyQt v6.10.0 Wheels for Testing

[Phil Thompson]

PyQt v6.10.0 is available for download at the local PyPI server for 
testing. The corresponding Qt6 wheels are also there. I'll move them to 
pypi.org around the middle of next week if there are no problems.

I've held back on the new QRangeModel as I'm still playing around with 
it. It has the potential to be very useful (or not).

The distro Qt use to build for Linux on Intel has changed from RHEL8 to 
RHEL9. This means that it now depends on GLIBC 2.34.

Phil