bug#57136: Snakemake cannot execute remote jobs

[Matthieu Simonin]

Hi there,

I've taken a stab at using it and restoring the patch as Konrad pointed seems 
the way to go.

But I also found that the package definition doesn't follow the guidelines[1] 
regarding the inputs definition.
One should use `propagated-inputs` instead of `inputs` for a python package.

In the current situation we can't invoke `snakemake` as a module:
`python -m snakemake` fails as the input dependencies aren't linked in the guix 
profile.

This way of invoking snakemake is used internally by snakemake here and there (for instance when calling the unit tests 
generated by `snakemake --generate-unit-tests`[2][3].

[1]: https://guix.gnu.org/manual/en/html_node/package-Reference.html
[2]: https://snakemake.readthedocs.io/en/stable/snakefiles/testing.html
[3]: 
https://github.com/snakemake/snakemake/blob/v7.7.0/snakemake/unit_tests/templates/ruletest.py.jinja2