warning during CI builds

[jepler]

I noticed this:

/tmp/build-env-4g46qohc/lib/python3.11/site-packages/setuptools/command/build_py.py:212: _Warning: Package 'adafruit_imageload.pnm.pgm' is absent from the `packages` configuration.
!!

        ********************************************************************************
        ############################
        # Package would be ignored #
        ############################
        Python recognizes 'adafruit_imageload.pnm.pgm' as an importable package[^1],
        but it is absent from setuptools' `packages` configuration.

        This leads to an ambiguous overall configuration. If you want to distribute this
        package, please make sure that 'adafruit_imageload.pnm.pgm' is explicitly added
        to the `packages` configuration field.

        Alternatively, you can also rely on setuptools' discovery methods
        (for example by using `find_namespace_packages(...)`/`find_namespace:`
        instead of `find_packages(...)`/`find:`).

        You can read more about "package discovery" on setuptools documentation page:

        - https://setuptools.pypa.io/en/latest/userguide/package_discovery.html

        If you don't want 'adafruit_imageload.pnm.pgm' to be distributed and are
        already explicitly excluding 'adafruit_imageload.pnm.pgm' via
        `find_namespace_packages(...)/find_namespace` or `find_packages(...)/find`,
        you can try to use `exclude_package_data`, or `include-package-data=False` in
        combination with a more fine grained `package-data` configuration.

        You can read more about "package data files" on setuptools documentation page:

        - https://setuptools.pypa.io/en/latest/userguide/datafiles.html


        [^1]: For Python, any directory (with suitable naming) can be imported,
              even if it does not contain any `.py` files.
              On the other hand, currently there is no concept of package data
              directory, all directories are treated like packages.
        ********************************************************************************

[tekktrik]

I think fixing this is going to require modifying the build scripts for building things in https://github.com/adafruit/circuitpython-build-tools. I think we could make it accept a greater-than-one element list for tool.setuptools.py-modules or tool.setuptools.packages, and then just only use the first one it gets (which should typically be the overall package. This also then silences the warning.

[tekktrik]

The wackier (but technically viable) option is to create a custom table named circuitpython-build-tools and use it like so:

[circuitpython-build-tools]
library = "adafruit_imageload"

We would change change the target table we're looking at. Has the nice benefit of being the same and unchange regardless of whether it's a module or package (or changes between them), but would be a patch. It's also a little overboard compared to the above.