check if memberships is none

shared/people_import.py

@@ -451,6 +451,9 @@ class PeopleTeamImporter(ImporterMixin):
         users = []
 
         for node in result["allTeams"]["edges"]:
+            if node["node"]["memberships"] is None:
+                continue
+            
             for membership in node["node"]["memberships"].sort(
                 key=lambda membership: membership["roleOrder"],
                 reverse=True