Bump urllib3 from 1.25.3 to 1.25.8

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.25.3 to 1.25.8.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.25.3...1.25.8)

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

requirements.txt

@@ -42,7 +42,7 @@ PySocks==1.7.0
 requests-oauthlib==1.2.0
 six==1.12.0
 typed-ast==1.4.0
-urllib3==1.25.3
+urllib3==1.25.8
 webencodings==0.5.1
 Werkzeug==0.15.5
 wrapt==1.11.2