Update datasets to 2.15.0
Update datasets to 2.15.0: https://github.com/huggingface/datasets/releases/tag/2.15.0

Related to:
- #1956
Update datasets to 2.15.0: Update datasets to 2.15.0: https://github.com/huggingface/datasets/releases/tag/2.15.0

Related to:
- #1956