Upgrade to datasets 4.0 (#924)
* remove trust remote code for datasets and bump datasets to 4.0
* remove trust remote code for datasets in extended tasks
* remove trust remote code for datasets in multilingual tasks
* fixing tasks for datasets 4.0
* fixing custom task loading to be compatible with datasets 4.0
* fix lcb
* revert main_tasks.py
* revert registry.py
* raise instead of assert
