paperwork: Fix regression in Shopleads mailing list membership

paperwork/api.py

@@ -49,17 +49,12 @@ class DepartmentViewSet(viewsets.ModelViewSet):
             "shop_lead_flag__members",
         )
         lists: dict[str, MailingList] = {}
-        shopleads: dict[Member, list[Department]] = {}
         for department in departments.filter(has_mailing_list=True):
             if department.shop_lead_flag is not None:
                 moderator_emails = {
                     member.volunteer_email if member.volunteer_email else member.email
                     for member in department.shop_lead_flag.members.all()
                 }
-                for member in department.shop_lead_flag.members.all():
-                    if member not in shopleads:
-                        shopleads[member] = []
-                    shopleads[member].append(department)
             else:
                 moderator_emails = set()
 
@@ -98,6 +93,13 @@ class DepartmentViewSet(viewsets.ModelViewSet):
             if department.parent_id is None:
                 recurse_children(department)
 
+        shopleads: dict[Member, list[Department]] = {}
+        for department in departments.filter(shop_lead_flag__isnull=False):
+            for member in department.shop_lead_flag.members.all():
+                if member not in shopleads:
+                    shopleads[member] = []
+                shopleads[member].append(department)
+
         # Add members to the Shop Leads mailing list, but don't configure it
         lists["ShopLeads"] = {
             "members": {