Merge pull request #2489 from python-trio/dependabot/pip/urllib3-1.26.13

Bump urllib3 from 1.26.12 to 1.26.13

Author: pquentin

docs-requirements.txt

@@ -90,7 +90,7 @@ tomli==2.0.1
     # via towncrier
 towncrier==22.8.0
     # via -r docs-requirements.in
-urllib3==1.26.12
+urllib3==1.26.13
     # via requests
 
 # The following packages are considered to be unsafe in a requirements file: