Upgrade client to PyQt6

[Abe404]

Right now running the client on Mac with an M1/M2 chip requires using Rosetta. It would be better not to have to do this, but the client must be updated to PyQt6.

To run with Rosetta
https://dev.to/courier/tips-and-tricks-to-setup-your-apple-m1-for-development-547g

I know from the 2D version that this upgrade can be a hassle, so I will try to address it as an isolated issue to avoid blocking other tasks.