Bump urllib3 from 1.25.9 to 1.26.5 in /requirements

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.25.9 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/1.25.9...1.26.5)

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

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

requirements/prod.txt

@@ -14,5 +14,5 @@ selenium==3.141.0
 six==1.15.0
 soupsieve==2.0.1
 stem==1.8.0
-urllib3==1.25.9
+urllib3==1.26.5
 xlrd==1.2.0