Fix xdoc run squad

[k22036]

Fix datasets library usage, introducing the evaluate library, and modifying the metric loading function.

Dependency updates:

• xdoc/fine_tuning/squad/requirements.txt: Removed version constraint for datasets and added the evaluate library.

Code fixes:

• xdoc/fine_tuning/squad/run_squad.py: Replaced load_metric from datasets with evaluate.load for loading metrics.

[k22036]

@microsoft-github-policy-service agree