Bump certifi from 2019.3.9 to 2023.7.22 in /ci

Bumps [certifi](https://github.com/certifi/python-certifi) from 2019.3.9 to 2023.7.22.
- [Commits](certifi/python-certifi@2019.03.09...2023.07.22)

---
updated-dependencies:
- dependency-name: certifi
  dependency-type: indirect
...

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

ci/requirements-docs.txt

@@ -8,7 +8,7 @@ alabaster==0.7.12
     # via sphinx
 babel==2.9.1
     # via sphinx
-certifi==2019.3.9
+certifi==2023.7.22
     # via requests
 chardet==3.0.4
     # via requests