canio: Correct type annotations of CAN.send, Listener.receive

shared-bindings/canio/CAN.c

@@ -324,7 +324,7 @@ STATIC const mp_obj_property_t canio_can_loopback_obj = {
 };
 
 
-//|     def send(message: Message) -> None:
+//|     def send(message: Union[RemoteTransmissionRequest, Message]) -> None:
 //|         """Send a message on the bus with the given data and id.
 //|         If the message could not be sent due to a full fifo or a bus error condition, RuntimeError is raised.
 //|         """

shared-bindings/canio/Listener.c

@@ -38,7 +38,7 @@
 //|     `~canio.CAN.listen`."""
 //|
 
-//|     def receive(self) -> Optional[Message]:
+//|     def receive(self) -> Optional[Union[RemoteTransmissionRequest,Message]]:
 //|         """Reads a message, after waiting up to self.timeout seconds
 //|
 //|         If no message is received in time, None is returned.  Otherwise,