Bump urllib3 from 2.6.0 to 2.6.3 in /ci (#149)

Author: dependabot[bot]

ci/requirements-docs.txt

@@ -44,5 +44,5 @@ sphinx==1.8.5
     # via -r requirements-docs.in
 sphinxcontrib-websupport==1.1.0
     # via sphinx
-urllib3==2.6.0
+urllib3==2.6.3
     # via requests