fs imports grp in bw_processing, which is not supported in WASM

[michaelweinold]

Calling

bw2io.add_example_database(searchable=False)

causes an error:

File /lib/python3.11/site-packages/fs/osfs.py:226, in OSFS._make_access_from_stat(cls, stat_result)
    224 access["uid"] = uid = stat_result.st_uid
    225 if not _WINDOWS_PLATFORM:
--> 226     import grp
    227     import pwd
    229     try:

ModuleNotFoundError: The module 'grp' is removed from the Python standard library in the Pyodide distribution due to browser limitations.
See https://pyodide.org/en/stable/usage/loading-packages.html for more details.

While this was patched by @cmutel in:

• bw_processing.datapackage.fs.close() uses grp (which is not available in Pyodide) #38
• bw2data error with config.is_test #39

It would be best to switch to fsspec in bw_processing.