Testing with pyqt6

[jdha]

There are issues with the current pyqt5 on M1/M2 Apple

Work arounds are to brew install pyqt@5 or use rosetta to emulate intel

Test leap to pyqt6

[jdha]

there is no conda-forge implementation of pyqt6 - so we build from pip

minimal updates required for a pyBDY build

[jdha]

benchmark test passes