dependency: (deps): bump pydantic from 2.7.3 to 2.7.4 in /backend (#145)

Bumps [pydantic](https://github.com/pydantic/pydantic) from 2.7.3 to 2.7.4.
- [Release notes](https://github.com/pydantic/pydantic/releases)
- [Changelog](https://github.com/pydantic/pydantic/blob/main/HISTORY.md)
- [Commits](pydantic/pydantic@v2.7.3...v2.7.4)

---
updated-dependencies:
- dependency-name: pydantic
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

backend/requirements.txt

@@ -36,7 +36,7 @@ pdfminer.six==20231228
 pillow==10.3.0
 psycopg2==2.9.9
 pycparser==2.22
-pydantic==2.7.3
+pydantic==2.7.4
 pydantic_core==2.18.4
 PyJWT==2.8.0
 pymongo==4.7.3