Modernize nimi-python setup.py projects with pyproject.toml

[ni-jfitzger]

We've started receiving messages like this during codegen:

/tmp/build-env-w9fmceq7/lib/python3.12/site-packages/setuptools/dist.py:759: SetuptoolsDeprecationWarning: License classifiers are deprecated.
!!

        ********************************************************************************
        Please consider removing the following classifiers in favor of a SPDX license expression:

        License :: OSI Approved :: MIT License

        See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
        ********************************************************************************

!!
  self._finalize_license_expression()

This is telling us to stop specifying "License :: OSI Approved :: MIT License" in the setup.py classifiers in favor of this SPDX format ... in a pyproject.toml, which we don't have.

---

The pyproject.toml format wants us to specify something like

[project]
license = "MIT"
license-files = ["LICENSE", "NILICENSE"]

Maybe we would need to AND with another license in the "license" field for the "NI General Purpose EULA" that's covered in the NILICENSE file. This may be a bigger discussion that we need to have internally.

---

Before we can do that, though, we'll first need to add a pyproject.toml.
See https://packaging.python.org/en/latest/guides/modernize-setup-py-project/#modernize-setup-py-project

Although pyproject.toml is not required yet, it's strongly recommended.