No dependency results when scanning celery-5.2.7.tar.gz

[JonoYang]

Originally reported at aboutcode-org/scancode.io#516

I've downloaded, extracted, and run a package scan on https://files.pythonhosted.org/packages/ce/21/41a0028f6d610987c0839250357c1a00f351790b8a448c2eb323caa719ac/celery-5.2.7.tar.gz but no dependency results show up in the top-level dependencies field.

I think this is due to the pypi package parser getting results from the celery-5.2.7/PKG-INFO file at the root of the codebase, but it cannot find any of the dependency versions and other info because the PKG-INFO file is not in an .egg-info directory. When running the package scanning debug flags, I see that we get the dependencies when we scan celery-5.2.7/celery.egg-info/PKG-INFO.

[JonoYang]

Fix merged in #3091