chore(deps): bump datasets from 2.15.0 to 2.18.0 in /backend

Bumps [datasets](https://github.com/huggingface/datasets) from 2.15.0 to 2.18.0.
- [Release notes](https://github.com/huggingface/datasets/releases)
- [Commits](huggingface/datasets@2.15.0...2.18.0)

---
updated-dependencies:
- dependency-name: datasets
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

backend/requirements.txt

@@ -7,7 +7,7 @@ asyncpg==0.29.0
 bcrypt==4.0.1
 black==24.3.0
 colorama==0.4.6
-datasets==2.15.0
+datasets==2.18.0
 email_validator==2.1.1
 fastapi==0.110.0
 greenlet==3.0.3