build(deps): bump certifi from 2022.12.7 to 2023.7.22 in /docs

Bumps [certifi](https://github.com/certifi/python-certifi) from 2022.12.7 to 2023.7.22.
- [Commits](certifi/python-certifi@2022.12.07...2023.07.22)

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

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

docs/requirements.txt

@@ -3,7 +3,7 @@ Babel==2.11.0
 blockdiag==3.0.0
 breathe==4.33.0
 brotlipy==0.7.0
-certifi==2022.12.7
+certifi==2023.7.22
 cffi==1.15.1
 charset-normalizer==2.1.1
 colorama==0.4.6