Update datasets dependency to 2.13.0 version
After 2.13.0 datasets release, update dependencies on it.

Note that I have also removed the explicit dependency on `datasets` from `services/api`,
- see commit: https://github.com/huggingface/datasets-server/commit/a2c0cd908b45a7065d936964c4d0477143146d6c

This is analogous to what was previously done on `services/worker`.
- See discussion: https://github.com/huggingface/datasets-server/pull/1147#issuecomment-1539883057
- See commit: https://github.com/huggingface/datasets-server/pull/1147/commits/4163a18ec561ddf93f93c096d76c2b06cf652f4d

Fix #1370.
Update datasets dependency to 2.13.0 version: After 2.13.0 datasets release, update dependencies on it.

Note that I have also removed the explicit dependency on `datasets` from `services/api`,
- see commit: https://github.com/huggingface/datasets-server/commit/a2c0cd908b45a7065d936964c4d0477143146d6c

This is analogous to what was previously done on `services/worker`.
- See discussion: https://github.com/huggingface/datasets-server/pull/1147#issuecomment-1539883057
- See commit: https://github.com/huggingface/datasets-server/pull/1147/commits/4163a18ec561ddf93f93c096d76c2b06cf652f4d

Fix #1370.