fix lint

Signed-off-by: Patricia Reinoso <patricia.reinoso@canonical.com>

src/charm.py

@@ -170,6 +170,7 @@ def _on_start_simulation_action(self, event: ActionEvent) -> None:
 
     def _generate_network_annotations(self) -> List[NetworkAnnotation]:
         """Generates a list of NetworkAnnotations to be used by gnbsim's StatefulSet.
+
         Returns:
             List[NetworkAnnotation]: List of NetworkAnnotations
         """