ci: bump urllib3 from 2.5.0 to 2.6.0 in /test/requirements

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: direct:production
  update-type: version-update:semver-minor
...

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

test/requirements/python-requirements.txt

@@ -4,4 +4,4 @@ packaging==25.0
 pytest==9.0.1
 pytest-ignore-flaky==2.2.1
 requests==2.32.5
-urllib3==2.5.0
+urllib3==2.6.0