chore: Decide on a Python type checker and implement in Prek

[MyPy](https://www.mypy-lang.org/) has traditionally been used for type checking, however there are newer type checkers on the market.

- [ty](https://docs.astral.sh/ty/)
- [pyrefly.org/](http://pyrefly.org/)

I'm already discounting `pyright` and `mypy` as they are too slow.

A Ty/Pyrefly comparison is available at: https://pydevtools.com/handbook/explanation/ty-vs-pyrefly/. PyCharm also leans toward pyrefly: https://www.jetbrains.com/help/pycharm/python-type-engine.html#pyrefly

- Investigate which of these options to pick
- Write an ADR
- Implement in the project and fix any errors
- Implement in Prek