build(deps): bump urllib3 from 2.0.3 to 2.0.6 in /requirements

Bumps [urllib3](https://github.com/urllib3/urllib3) from 2.0.3 to 2.0.6.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@2.0.3...2.0.6)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: indirect
...

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

requirements/docs.txt

@@ -11,12 +11,10 @@ charset-normalizer==3.2.0
 docutils==0.18.1
 idna==3.4
 imagesize==1.4.1
-importlib-metadata==6.8.0
 jinja2==3.1.2
 markupsafe==2.1.3
 packaging==23.1
 pygments==2.15.1
-pytz==2023.3
 requests==2.31.0
 snowballstemmer==2.2.0
 sphinx==6.2.1
@@ -28,5 +26,4 @@ sphinxcontrib-jquery==4.1
 sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.3
 sphinxcontrib-serializinghtml==1.1.5
-urllib3==2.0.3
-zipp==3.16.2
+urllib3==2.0.6