Add requirement to fs module

[tngTUDOR]

Current

the package depends on the fs module, but does not declare a dependency on it. An environment created with conda/mamba does not automatically pull the fs module dep.

mamba create -n bw2-data-fs-mamba python=3
mamba activate bw2-data-fs-mamba
mamba install -c cmutel bw2data

mamba list | egrep "bw"
# packages in environment at /home/good-omens-glasses/miniforge3/envs/bw2-data-fs-mamba:
bw2data                   4.0.dev40                  py_0    cmutel
bw2parameters             0.7                        py_0    cmutel
bw_processing             0.9.5              pyhd8ed1ab_0    conda-forge

mamba list | egrep "fs"

yields:

mamba list | egrep "fs"
# packages in environment at /home/good-omens-glasses/miniforge3/envs/bw2-data-fs-mamba:

fs                        2.4.16             pyhd8ed1ab_0    conda-forge
fsspec                    2024.6.0           pyhff2d567_0    conda-forge
morefs                    0.2.0                      py_0    cmutel

while installing bw2data with pip does pull it:

bw2analyzer          0.11.8
bw2calc              2.0.dev16
bw2data              4.0.dev33
bw2parameters        1.1.0

pip list | egrep "fs"
fs                   2.4.16

pipdeptree analysis:

├── bw-migrations [required: >=0.2, installed: 0.2]
│   ├── bw2data [required: Any, installed: 4.0.dev33]
│   │   ├── bw-processing [required: Any, installed: 0.9]
│   │   │   ├── fs [required: Any, installed: 2.4.16]
...

[tngTUDOR]

(Sorry, maybe I'm only having a conversation with myself with this issue 🫣 🤫)

[cmutel]

Mixed in 4.0.dev41