The api and rows services cannot store datasets cache
The datasets cache, for api and rows services (they depend on datasets), is not set, and by default is `/.cache/huggingface/datasets`. But this directory is not accessible by the python user.

I'm not sure if it's an issue, but I think we should:
- set the datasets environment variable for these services (note that all the pods that depend on libcommon potentially have the same issue, but not all of them use datasets)
- or better (but it's more work) create a `libs/libdatasets` library, that should only be used by /rows and the workers

The api and rows services cannot store datasets cache: The datasets cache, for api and rows services (they depend on datasets), is not set, and by default is `/.cache/huggingface/datasets`. But this directory is not accessible by the python user.

I'm not sure if it's an issue, but I think we should:
- set the datasets environment variable for these services (note that all the pods that depend on libcommon potentially have the same issue, but not all of them use datasets)
- or better (but it's more work) create a `libs/libdatasets` library, that should only be used by /rows and the workers
