Migrate to pyproject.toml

[tmorrell]

Description

Will need to switch to pyproject.toml to avoid depreciation warning

 DEPRECATION: Legacy editable install of iga==1.3.5 from file:///Users/tmorrell/Documents/iga (setup.py develop) is deprecated. pip 25.0 will enforce this behaviour change. A possible replacement is to add a pyproject.toml or enable --use-pep517, and use setuptools >= 64. If the resulting installation is not behaving as expected, try using --config-settings editable_mode=compat. Please consult the setuptools documentation for more information. Discussion can be found at https://github.com/pypa/pip/issues/11457