Always return an updatedUploadPort.

Arduino CLI should always return the port after an upload, even in the case
where no port change is expected. The consumer shouldn't be required to
implement "if not updated_upload_port, use original port" logic.

The whole point is that all the logic for determining which port should be
selected after an upload should be implemented in Arduino CLI. The consumer
should be able to simply select the port Arduino CLI tells it to select in
all cases.

commands/upload/upload.go

@@ -201,7 +201,7 @@ func UsingProgrammer(ctx context.Context, req *rpc.UploadUsingProgrammerRequest,
 func runProgramAction(pme *packagemanager.Explorer,
 	sk *sketch.Sketch,
 	watch <-chan *rpc.BoardListWatchResponse,
-	importFile, importDir, fqbnIn string, port *rpc.Port,
+	importFile, importDir, fqbnIn string, userPort *rpc.Port,
 	programmerID string,
 	verbose, verify, burnBootloader bool,
 	outStream, errStream io.Writer,
@@ -212,6 +212,7 @@ func runProgramAction(pme *packagemanager.Explorer,
 		go f.DiscardCh(watch)
 	}()
 
+	port := userPort
 	if port == nil || (port.Address == "" && port.Protocol == "") {
 		// For no-port uploads use "default" protocol
 		port = &rpc.Port{Protocol: "default"}
@@ -519,7 +520,11 @@ func runProgramAction(pme *packagemanager.Explorer,
 	uploadCompleted()
 	logrus.Tracef("Upload successful")
 
-	return updatedUploadPort.Await(), nil
+	updatedPort := updatedUploadPort.Await()
+	if updatedPort == nil {
+		updatedPort = userPort
+	}
+	return userPort, nil
 }
 
 func detectUploadPort(uploadCtx context.Context, uploadPort *rpc.Port, watch <-chan *rpc.BoardListWatchResponse, result f.Future[*rpc.Port]) {