WIP - SW forward with DVS

added missing return type hint

sinabs/backend/dynapcnn/dynapcnnnetwork_module.py

@@ -110,7 +110,7 @@ def get_exit_layers(self) -> List[int]:
             if any(d < 0 for d in destinations)
         ]
 
-    def get_exit_points(self):
+    def get_exit_points(self) -> Dict[int, Dict]:
         """ Get details of layers that act as exit points of the network
         
         Returns