Use pyproject.toml for package configuration

[jack-fs]

There is a shift towards using pyproject.toml instead of setup.py for package configuration.
This has the benefit of being statically inspectable without running the config, and allows many tools to be used for dependency management, while using the toml file as a single source of truth. An overview can be found here and in the motivation section of PEP621.

See the python docs for declaring project metadata, which is the (living) specification for the format of the pyproject.toml file

Relevant PEPs:

• 517
• 518
• 621
• 660

With setuptools recently implementing support for PEP660, it seems that there's very little reason not to do it