Bump pydantic-core from 2.20.1 to 2.39.0

Bumps [pydantic-core](https://github.com/pydantic/pydantic-core) from 2.20.1 to 2.39.0.
- [Release notes](https://github.com/pydantic/pydantic-core/releases)
- [Commits](pydantic/pydantic-core@v2.20.1...v2.39.0)

---
updated-dependencies:
- dependency-name: pydantic-core
  dependency-version: 2.39.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

app/backend/requirements.txt

@@ -339,7 +339,7 @@ pycparser==2.22
     # via cffi
 pydantic==2.8.2
     # via openai
-pydantic-core==2.20.1
+pydantic-core==2.39.0
     # via pydantic
 pygments==2.18.0
     # via rich