fix: Resolve setuptools warnings

[andersk]

Resolve these warnings from PYTHONDEVMODE=1 uv build:

…/lib/python3.12/site-packages/setuptools/dist.py:493: SetuptoolsDeprecationWarning: Invalid dash-separated options
!!

        ********************************************************************************
        Usage of dash-separated 'description-file' will not be supported in future
        versions. Please use the underscore name 'description_file' instead.

        This deprecation is overdue, please update your project and remove deprecated
        calls to avoid build errors in the future.

        See https://setuptools.pypa.io/en/latest/userguide/declarative_config.html for details.
        ********************************************************************************

!!
  opt = self.warn_dash_deprecation(opt, section)

…/lib/python3.12/site-packages/setuptools/_distutils/dist.py:270: UserWarning: Unknown distribution option: 'help_center'
  warnings.warn(msg)

…/lib/python3.12/site-packages/setuptools/_distutils/cmd.py:124: SetuptoolsDeprecationWarning: bdist_wheel.universal is deprecated
!!

        ********************************************************************************
        With Python 2.7 end-of-life, support for building universal wheels
        (i.e., wheels that support both Python 2 and Python 3)
        is being obviated.
        Please discontinue using this option, or if you still need it,
        file an issue with pypa/setuptools describing your use case.

        By 2025-Aug-30, you need to update your project and remove deprecated calls
        or your builds will no longer be supported.
        ********************************************************************************

!!
  self.finalize_options()

…/lib/python3.12/site-packages/setuptools/dist.py:751: 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()

warning: no files found matching '*' under directory 'twilio/conf'

Checklist

• I acknowledge that all my contributions will be made under the project's license
• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have read the Contribution Guidelines and my PR follows them
• I have titled the PR appropriately
• I have updated my branch with the main branch
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation about the functionality in the appropriate .md file
• I have added inline documentation to the code I modified

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