Bump urllib3 from 1.25.3 to 1.26.17

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.25.3 to 1.26.17.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.25.3...1.26.17)

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

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

requirements-dev.txt

@@ -53,7 +53,7 @@ tox==3.24.4
 tox-pip-extensions==1.6.0
 typed-ast==1.4.3
 typing-extensions==3.7.4
-urllib3==1.25.3
+urllib3==1.26.17
 virtualenv==20.6.0
 wcwidth==0.1.7
 webcolors==1.9.1