refactor: deprecate hostname attribute from ModuleSystem (#30308)

The hostname constructor argument of the XModule ModuleSystem is deprecated
in favour of directly accessing the LMS_BASE value from django.conf.settings.

lms/djangoapps/courseware/tests/test_lti_integration.py

@@ -43,7 +43,7 @@ class TestLTI(BaseTestXmodule):
         context_id = str(self.item_descriptor.course_id)
         user_service = self.item_descriptor.xmodule_runtime.service(self.item_descriptor, 'user')
         user_id = str(user_service.get_current_user().opt_attrs.get(ATTR_KEY_ANONYMOUS_USER_ID))
-        hostname = self.item_descriptor.xmodule_runtime.hostname
+        hostname = settings.LMS_BASE
         resource_link_id = str(urllib.parse.quote(f'{hostname}-{self.item_descriptor.location.html_id()}'))
 
         sourcedId = "{context}:{resource_link}:{user_id}".format(