change: remove two setuptools deprecations

Remove the following deprecations:

```
    /home/jjerphan/.local/share/mambaforge/envs/sdk/lib/python3.11/site-packages/setuptools/dist.py:498: 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)
    /home/jjerphan/.local/share/mambaforge/envs/sdk/lib/python3.11/site-packages/setuptools/config/setupcfg.py:293: _DeprecatedConfig: Deprecated config in `setup.cfg`
    !!

            ********************************************************************************
            The license_file parameter is deprecated, use license_files instead.

            By 2023-Oct-30, you need to update your project and remove deprecated calls
            or your builds will no longer be supported.

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

    !!
      parsed = self.parsers.get(option_name, lambda x: x)(value)
    running develop
```

Signed-off-by: Julien Jerphanion <[email protected]>

Author: jjerphan

setup.cfg

@@ -8,8 +8,8 @@ testpaths = tests
 test=pytest
 
 [metadata]
-description-file = README.rst
-license_file = LICENSE.txt
+description_file = README.rst
+license_files = LICENSE.txt
 
 [wheel]
 universal = 1