Bump urllib3 from 1.26.5 to 1.26.17 in /docs (#100)

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.5 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@1.26.5...1.26.17)

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

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

docs/requirements.txt

@@ -53,7 +53,7 @@ sphinxcontrib-serializinghtml==1.1.4
 testpath==0.4.4
 tornado==6.3.2
 traitlets==4.3.3
-urllib3==1.26.5
+urllib3==1.26.17
 webencodings==0.5.1
 zipp==3.4.0
 exhale==0.2.3