[Build] QA warning about codespell_lib.tests being installed as data

[waebbl]

While packaging v2.2.0 for Gentoo Linux, I got a QA notice about this:

* QA Notice: setuptools warnings detected:
 * 
 *          Installing 'codespell_lib.tests' as data is deprecated, please list it in `packages`.

The actual setuptools warning is as (here shown for Python 3.11, but same for 3.10)

/usr/lib/python3.11/site-packages/setuptools/command/build_py.py:202: SetuptoolsDeprecationWarning:     Instal
ling 'codespell_lib.tests' as data is deprecated, please list it in `packages`.
    !!


    ############################
    # Package would be ignored #
    ############################
    Python recognizes 'codespell_lib.tests' as an importable package,
    but it is not listed in the `packages` configuration of setuptools.

    'codespell_lib.tests' has been automatically added to the distribution only
    because it may contain data files, but this behavior is likely to change
    in future versions of setuptools (and therefore is considered deprecated).

    Please make sure that 'codespell_lib.tests' is included as a package by using
    the `packages` configuration field or the proper discovery methods
    (for example by using `find_namespace_packages(...)`/`find_namespace:`
    instead of `find_packages(...)`/`find:`).

    You can read more about "package discovery" and "data files" on setuptools
    documentation page.


!!

  check.warn(importable)

Find attached the full build log.
codespell-2.2.0:20220818-083735.log

[luzpaz]

Thanks for reporting @waebbl
CC @larsoner if you have a moment, do you mind looking in to this?