Several behind-the-scenes changes in this PR, including:
Updating the PyQt dependency from PyQt5 to PyQt6. This is the current latest one, easy to install Qt6 via brew or apt-get, and has compiled wheels for all modern platforms including Macs with Apple Silicon.
Rewrote the setup & installers to be PEP-517 modern style.
Removed "mpf" as a Python dependency. This will allow mpf-monitor to work with other mpf distributions with different names (such as "fast-mpf"). If someone somehow installs mpf-monitor without having mpf installed, then the command "mpf monitor" will fail and they will figure out that they need an mpf distribution. :) Also if mpf is installed after mpf-monitor, everything still works.
Several behind-the-scenes changes in this PR, including: