setuptools and Cython should not be listed as requirements

[SpecLad]

This project does not appear to use either setuptools or Cython at runtime, so these packages should not be listed in requirements.txt. Listing them there causes unnecessary packages to be installed into the user's environment.

They are build-time dependencies, so they should be listed in pyproject.toml instead. See pycocotools for an example: https://github.com/ppwwyyxx/cocoapi/blob/4670067b35e7b65d618c9746c456fe2c1128049c/PythonAPI/pyproject.toml.