dependency: (deps): bump certifi from 2023.11.17 to 2024.7.4 in /backend

Bumps [certifi](https://github.com/certifi/python-certifi) from 2023.11.17 to 2024.7.4.
- [Commits](certifi/python-certifi@2023.11.17...2024.07.04)

---
updated-dependencies:
- dependency-name: certifi
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

backend/requirements.txt

@@ -1,5 +1,5 @@
 asgiref==3.7.2
-certifi==2023.11.17
+certifi==2024.7.4
 charset-normalizer==3.3.2
 coreapi==2.3.3
 coreschema==0.0.4