Bump urllib3 from 1.22 to 1.26.5

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.22 to 1.26.5.
- [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/1.22...1.26.5)

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

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

requirements.txt

@@ -46,7 +46,7 @@ terminado==0.8.1
 testpath==0.3.1
 tornado==4.5.3
 traitlets==4.3.2
-urllib3==1.22
+urllib3==1.26.5
 wcwidth==0.1.7
 webencodings==0.5.1
 widgetsnbextension==3.1.3