build(deps): bump certifi from 2021.10.8 to 2024.7.4 in /docs

Bumps [certifi](https://github.com/certifi/python-certifi) from 2021.10.8 to 2024.7.4.
- [Commits](certifi/python-certifi@2021.10.08...2024.07.04)

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

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

docs/requirements.txt

@@ -9,7 +9,7 @@ babel==2.9.1; python_version >= "3.6" and python_full_version < "3.0.0" or pytho
 backcall==0.2.0; python_full_version >= "3.6.2" and python_version >= "3.8"
 black==22.1.0; python_full_version >= "3.6.2"
 bleach==4.1.0; python_full_version >= "3.7.1" and python_version < "4" and python_version >= "3.7"
-certifi==2021.10.8; python_full_version >= "3.6.0" and python_version >= "3.6"
+certifi==2024.7.4; python_full_version >= "3.6.0" and python_version >= "3.6"
 cffi==1.15.0; implementation_name == "pypy" and python_version >= "3.7" and python_full_version >= "3.6.1" and sys_platform == "linux"
 cfgv==3.3.1; python_full_version >= "3.6.1"
 charset-normalizer==2.0.12; python_full_version >= "3.6.0" and python_version >= "3.6"