Bump urllib3 from 2.6.0 to 2.6.3 in /requirements/test (#545)

Author: kurtmckee

requirements/test/requirements.txt

@@ -15,4 +15,4 @@ requests==2.32.5 ; python_version >= "3.10"
 responses==0.25.8 ; python_version >= "3.10"
 tomli==2.2.1 ; python_version >= "3.10" and python_full_version <= "3.11.0a6"
 typing-extensions==4.15.0 ; python_version == "3.10"
-urllib3==2.6.0 ; python_version >= "3.10"
+urllib3==2.6.3 ; python_version >= "3.10"