Bump urllib3 from 2.5.0 to 2.6.0 in /requirements/docs

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
...

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

requirements/docs/requirements.txt

diff --git a/requirements/docs/requirements.txt b/requirements/docs/requirements.txt
index 611f5a4..4dac49f 100644
--- a/requirements/docs/requirements.txt
+++ b/requirements/docs/requirements.txt
@@ -22,4 +22,4 @@
 sphinxcontrib-qthelp==2.0.0 ; python_version >= "3.10"
 sphinxcontrib-serializinghtml==2.0.0 ; python_version >= "3.10"
 tomli==2.3.0 ; python_version == "3.10"
-urllib3==2.5.0 ; python_version >= "3.10"
+urllib3==2.6.0 ; python_version >= "3.10"