chore: document attrs and setuptools dependencies in requirements.txt

[dlaehnemann]

The code uses import attr:
https://github.com/search?q=repo%3Aaertslab%2Fctxcore+attr&type=code

And from the syntax (for example attr.s and attr.ib()), I conclude that this must be using the attrs python package, see for example: https://www.attrs.org/en/stable/api-attr.html#attr.ib

This came up, because this dependency is also missing from the bioconda package and caused a ModuleNotFoundError: No module named 'attr' error in a downstream package. I'll also go and fix this there.

If I'm wrong with the package dependency, please correct me!

[dlaehnemann]

This now also documents the runtime dependency on setuptools.

pkg_resources are needed upon import ctxcore:

ctxcore/src/ctxcore/__init__.py

Line 5 in 190be03

from pkg_resources import DistributionNotFound, get_distribution

This came up in the bioconda recipe testing during the CI run there:

 17:03:45 BIOCONDA INFO (OUT) import: 'ctxcore'
17:03:45 BIOCONDA INFO (OUT) Traceback (most recent call last):
17:03:45 BIOCONDA INFO (OUT)   File "/opt/conda/conda-bld/ctxcore_1762966867340/test_tmp/run_test.py", line 2, in <module>
17:03:45 BIOCONDA INFO (OUT)     import ctxcore
17:03:45 BIOCONDA INFO (OUT)   File "/opt/conda/conda-bld/ctxcore_1762966867340/_test_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_/lib/python3.13/site-packages/ctxcore/__init__.py", line 5, in <module>
17:03:45 BIOCONDA INFO (OUT)     from pkg_resources import DistributionNotFound, get_distribution
17:03:45 BIOCONDA INFO (OUT) ModuleNotFoundError: No module named 'pkg_resources'

[dlaehnemann]

Just for the cross-referencing to go both ways, here's the fix in the bioconda recipe:
bioconda/bioconda-recipes#60658

[dlaehnemann]

As the most recent contributor, would you care to have a look, @ghuls ?