fix: give superusers all studio permissions

(cherry picked from commit 8ef55754f4a529cc6b784298320fcdb8b415bd83)
(cherry picked from commit 8e281a9)
(cherry picked from commit f552973)

common/djangoapps/student/roles.py

@@ -136,7 +136,7 @@ class GlobalStaff(AccessRole):
     The global staff role
     """
     def has_user(self, user):
-        return bool(user and user.is_staff)
+        return bool(user and (user.is_superuser or user.is_staff))
 
     def add_users(self, *users):
         for user in users: