Chore(deps): Update pydantic-settings requirement in /api/app (#111)

Updates the requirements on [pydantic-settings](https://github.com/pydantic/pydantic-settings) to permit the latest version.
- [Release notes](https://github.com/pydantic/pydantic-settings/releases)
- [Commits](pydantic/pydantic-settings@v2.2.1...v2.6.0)

---
updated-dependencies:
- dependency-name: pydantic-settings
  dependency-type: direct:production
...

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

api/app/requirements.txt

@@ -4,7 +4,7 @@ fastapi~=0.112.1
 SQLAlchemy~=2.0.32
 pydantic~=2.8.2
 cryptography~=43.0.1
-pydantic-settings~=2.2.1
+pydantic-settings~=2.6.0
 PyJWT~=2.9.0
 requests~=2.32.3
 pycryptodome~=3.20.0