chore(deps): bump urllib3 from 2.5.0 to 2.6.0 in /docs (#5920)

Bumps [urllib3](https://github.com/urllib3/urllib3) from 2.5.0 to 2.6.0.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](https://github.com/urllib3/urllib3/compare/2.5.0...2.6.0)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-version: 2.6.0
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

docs/requirements.txt

@@ -23,8 +23,6 @@ idna==3.7
     # via requests
 imagesize==1.4.1
     # via sphinx
-importlib-metadata==8.7.0
-    # via sphinx
 jinja2==3.1.6
     # via
     #   myst-parser
@@ -85,7 +83,5 @@ sphinxcontrib-serializinghtml==1.1.10
     # via sphinx
 sphinxcontrib-svg2pdfconverter==1.2.2
     # via -r requirements.in
-urllib3==2.5.0
+urllib3==2.6.0
     # via requests
-zipp==3.23.0
-    # via importlib-metadata