Switching to pyproject.toml for specifying package metadata

[matt-graham]

Switches from current setup.py approach of specifying package metadata to instead use a pyproject.toml configuration file and sets up setuptools_scm to automatically set package version number from Git release tags.

I think I've directly translated all the arguments passed to setup function in previous setup.py to equivalent pyproject.toml properties, so this should retain same metadata when publishing to PyPI, other than there was previously a slight typo in one argument (pacakge_data instead of package_data) which is now fixed. I've also added the additional requirements files as optional dependencies which can be installed with pip using the extras syntax, for example pip install s2fft[tests]. I also integrated the previous content in pytest.ini in to the pyproject.toml file.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.02%. Comparing base (76fa862) to head (7e94a9d).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #173   +/-   ##
=======================================
  Coverage   93.02%   93.02%           
=======================================
  Files          28       28           
  Lines        3109     3109           
=======================================
  Hits         2892     2892           
  Misses        217      217           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.