refactor: deprecate static_url argument from ModuleSystem

This argument was officially used only by the ProblemBlock.
If you need to get the base URL for static assets in your XBlock, please use
`settings.STATIC_URL` directly, instead of `runtime.STATIC_URL`.

lms/djangoapps/courseware/module_render.py

@@ -680,7 +680,6 @@ def get_module_system_for_user(
 
     system = LmsModuleSystem(
         track_function=track_function,
-        static_url=settings.STATIC_URL,
         get_module=inner_get_module,
         user=user,
         publish=publish,