build: tool.setuptools.namespaces = false

[yxtay]

What this PR does / why we need it:

https://setuptools.pypa.io/en/latest/userguide/package_discovery.html#custom-discovery
https://github.com/feast-dev/feast/blob/master/setup.py

Based on the documentation and following the setup.py that was based on, the namespace = false should be set in [tool.setuptools]

• In setup.py, find_packages was used instead of find_namespace_packages
• This will ensure that the docs and requirements folder are not errorneously included in the feast package
• Part of the reason why I want this is that the requirements.txt files in the requirements folder is being flagged out to contain vulnerable versions in container scans
  • This causes false positives in vulnerability notifications
• I'm also facing issues with vulnerabilities being flagged out due to versions in the package.json in the sdk/python/ui/package.json and the Dockerfiles in sdk/python/feast/infra/feature_servers/multicloud, but do not have any suggestions yet.
  • My sense is that sdk/python/ui should not be included in the python package, but I'm not sure what exactly is it's purpose and who uses it right now

Which issue(s) this PR fixes:

Misc