build(deps): bump urllib3 from 1.26.13 to 1.26.17 in /docs/.sphinx

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.13 to 1.26.17.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.13...1.26.17)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: direct:production
...

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

docs/.sphinx/pinned-requirements.txt

@@ -31,4 +31,4 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.3
 sphinxcontrib-serializinghtml==1.1.5
 tornado==6.3.3
-urllib3==1.26.13
+urllib3==1.26.17