move build configuration from setup.cfg to pyproject.toml

[zacharyburnett]

setuptools now supports the [project] table for project metadata, defined by PEP621.

Additionally, setuptools now supports its own entry in pyproject.toml called [tool.setuptools] (pypa/setuptools#1688, https://setuptools.pypa.io/en/latest/userguide/pyproject_config.html#setuptools-specific-configuration); however, it comes with the following disclaimer:

Support for declaring configurations not standardized by PEP 621 (i.e. the [tool.setuptools] table), is still in beta stage and might change in future releases.

Reading toml is supported natively in Python 3.11 with tomllib. Given this, we can consolidate the build configuration into a single pyproject.toml file that can possibly be read by other build systems in the future.

[pllim]

Are we reviving STScI package template? I don't think it is being maintained anymore.

https://github.com/OpenAstronomy/packaging-guide

[zacharyburnett]

Are we reviving STScI package template? I don't think it is being maintained anymore.

https://github.com/OpenAstronomy/packaging-guide

ah ok, I followed a reference from the INS guide so I assumed it was still current

[pllim]

Hmm even https://github.com/spacetelescope/ins-jwst-community-software has not been touched for a year. 🤷

[zacharyburnett]

I made an analogous PR to OpenAstronomy/packaging-guide#38; I'll keep this branch alive until we figure out if anyone is actually using this repo, and then if not we should probably archive it / indicate deprecation

[zacharyburnett]

ins-jwst-community-software now includes references to requiring pyproject.toml instead of setup.cfg: https://github.com/spacetelescope/ins-jwst-community-software/blob/db8c2e2ace4dca74304497191bc4e3a4a71e0745/tier1_standards/package_structure.md#useful-links

I will reopen this PR and make sure it is up-to-date