Fix warnings from docutils and pkg_resources

[hugovk]

pyroma/tests.py:8
  /Users/hugo/github/pyroma/pyroma/tests.py:8: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
    from pkg_resources import resource_filename, resource_string

pyroma/tests.py: 11 warnings
  /Users/hugo/github/pyroma/pyroma/ratings.py:426: PendingDeprecationWarning: Argument "writer_name" will be removed in Docutils 2.0.  Specify writer name in the "writer" argument.
    publish_parts(source=source, writer_name="html4css1", settings_overrides=settings)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

[hugovk]

Setuptools has now removed pkg_resources and main master is now failing:

• https://github.com/hugovk/pyroma/actions/runs/22033028930
• Remove pkg_resources pypa/setuptools#5007