Bump certifi from 2022.12.7 to 2023.7.22 in /doc/manual

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] <[email protected]>

Author: dependabot[bot]

doc/manual/requirements.txt

@@ -1,7 +1,7 @@
 alabaster==0.7.12
 Babel==2.10.1
 beautifulsoup4==4.11.1
-certifi==2022.12.7
+certifi==2023.7.22
 chardet==4.0.0
 charset-normalizer==2.0.12
 docutils==0.17.1