chore: Bump certifi from 2022.9.24 to 2022.12.7 in /tests/unit

Bumps [certifi](https://github.com/certifi/python-certifi) from 2022.9.24 to 2022.12.7.
- [Release notes](https://github.com/certifi/python-certifi/releases)
- [Commits](certifi/python-certifi@2022.09.24...2022.12.07)

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

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

tests/unit/requirements.txt

@@ -1,5 +1,5 @@
 attrs==22.1.0
-certifi==2022.9.24
+certifi==2022.12.7
 charset-normalizer==2.1.1
 coverage==6.5.0
 coveralls==3.3.1