Move from `setup.py` to `pyproject.toml`

Now that `pyproject.toml` is the standard and it can almost everything that can be done with `setup.py`, we should consider using it exclusively. The main thing with `pyproject.toml` is it is declarative as opposed to `setup.py` which is procedural.

The switch would additionally open the door to using other tools such as [hatch](https://github.com/pypa/hatch) to (See [here](https://hatch.pypa.io/1.12/why/) for a list and description of its advantages over setuptools and other tools)

At the very least we could move all the static metadata (e.g. package name, authors, description, license) from `setup.py` to `pyproject.toml`.