build(deps): bump urllib3 from 1.26.5 to 1.26.6 (#6235)

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.5 to 1.26.6.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/1.26.6/CHANGES.rst)
- [Commits](https://github.com/urllib3/urllib3/compare/1.26.5...1.26.6)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

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

test_requirements.txt

@@ -22,7 +22,7 @@ xmltodict==0.12.0
 google-compute-engine==2.8.13
 google-cloud-storage==1.39.0
 
-urllib3==1.26.5
+urllib3==1.26.6
 
 # required by collective.checkdocs
 Pygments==2.9.0