fix: skip notification insert for deleted user in channel member update

src/snek/service/notification.py

@@ -41,6 +41,8 @@ class NotificationService(BaseService):
             channel_member['new_count'] += 1
             
             usr = await self.services.user.get(uid=channel_member["user_uid"])
+            if not usr:
+                continue
             print("INSERTED FOR ",usr["username"],flush=True)
             await self.services.channel_member.save(channel_member)