[ENH] move pybids cache to workdir

[bpinsard]

The BIDSLayout is hard-coded to store it's sqlite database into the input folder.

giga_connectome/giga_connectome/utils.py

Line 42 in 556e81c

database_path=bids_dir,

However, one might have read-only access to that folder (or want to impose it through container binds to avoid any modification), causing it to crash with :

sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) unable to open database file

In nipreps softwares this is stored into the workdir where we expect write permissions.