Bump certifi from 2020.12.5 to 2022.12.7 in /backend/python

Bumps [certifi](https://github.com/certifi/python-certifi) from 2020.12.5 to 2022.12.7.
- [Release notes](https://github.com/certifi/python-certifi/releases)
- [Commits](certifi/python-certifi@2020.12.05...2022.12.07)

---
updated-dependencies:
- dependency-name: certifi
  dependency-type: direct:production
...

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

Author: dependabot[bot]

backend/python/requirements.txt

@@ -4,7 +4,7 @@ attrs==21.2.0
 black==20.8b1
 CacheControl==0.12.6
 cachetools==4.2.1
-certifi==2020.12.5
+certifi==2022.12.7
 cffi==1.14.5
 chardet==4.0.0
 click==7.1.2