Build includes docs package

[jaraco]

In the upstream skeleton @ jaraco/skeleton@63535c6, I began adopting the simpler default discovery for setuptools. For some projects like setuptools, however, the default discovery doesn't work because there are more than one top-level package. When I restored an explicit finder directive, I neglected to restore the finder exclusions, and now docs is getting included in the build:

 setuptools main @ pyproject-build .
* Creating venv isolated environment...
* Getting build dependencies for sdist...
running egg_info
...
creating '/Users/jaraco/code/pypa/setuptools/dist/.tmp-q39z981n/setuptools-69.0.3.post20240210-py3-none-any.whl' and adding 'build/bdist.macosx-14-arm64/wheel' to it
adding 'distutils-precedence.pth'
adding '_distutils_hack/__init__.py'
adding '_distutils_hack/override.py'
adding 'docs/conf.py'
adding 'pkg_resources/__init__.py'
...
adding 'setuptools-69.0.3.post20240210.dist-info/RECORD'
removing build/bdist.macosx-14-arm64/wheel
Successfully built setuptools-69.0.3.post20240210.tar.gz and setuptools-69.0.3.post20240210-py3-none-any.whl