Bump requests from 2.32.3 to 2.32.4 in /app/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: indirect
...

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

Author: dependabot[bot]

app/backend/requirements.txt

@@ -366,7 +366,7 @@ quart-cors==0.7.0
     # via -r requirements.in
 regex==2024.11.6
     # via tiktoken
-requests==2.32.3
+requests==2.32.4
     # via
     #   azure-core
     #   msal