Support load_setup_py_data

[maxnoe]

To avoid manual editing of recipes to update dependencies and entry points for recipes solely relying on building a setuptools project, being able to use {% set data = load_setup_py_data() %}.

Currently the linter will straight out fail if this is the case, see for example: https://github.com/conda-forge/staged-recipes/pull/12976#issuecomment-715376575

[jakirkham]

Certainly something like that would be nice. Unfortunately load_setup_py_data requires a setup.py file that already exists to work. IOW it won't work when the source needs to be downloaded from a remote location first.

Note that often the metadata is not totally reliable. So we probably still have to fill some things after that.

[maxnoe]

It worked locally for me but the linter just reused to check the file

[jakirkham]

Was the recipe already collocated with the source code?

[maxnoe]

No.