build: bump urllib3 from 1.26.18 to 1.26.19 in /.github/workflows

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.18 to 1.26.19.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/1.26.19/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.18...1.26.19)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: indirect
...

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

.github/workflows/mkdocs-requirements.txt

@@ -29,7 +29,7 @@ pyyaml-env-tag==0.1
 regex==2022.10.31
 requests==2.32.0
 six==1.16.0
-urllib3==1.26.18
+urllib3==1.26.19
 verspec==0.1.0
 watchdog==2.2.1
 zipp==3.17.0