Bump requests from 2.32.3 to 2.32.4 in /src/backend

Bumps [requests](https://github.com/psf/requests) from 2.32.3 to 2.32.4.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/main/HISTORY.md)
- [Commits](psf/requests@v2.32.3...v2.32.4)

---
updated-dependencies:
- dependency-name: requests
  dependency-version: 2.32.4
  dependency-type: direct:production
...

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

Author: dependabot[bot]

src/backend/requirements.txt

@@ -255,7 +255,7 @@ python-dotenv==1.0.1
     #   environs
 regex==2024.11.6
     # via tiktoken
-requests==2.32.3
+requests==2.32.4
     # via
     #   azure-core
     #   msal