Add retrieve result test and correct lock in sqlalchemy

hub/persistence/repositories/city.py

@@ -130,8 +130,6 @@ class City(Repository):
       result_set = self.session.execute(
         select(Model).where(Model.user_id == user_id, Model.application_id == application_id)
       )
-      self.session.close()
-      self.session = Session(self.engine)
       return [r[0] for r in result_set]
     except SQLAlchemyError as err:
       logging.error('Error while fetching city by name %s', err)