refactor: optimize user reader and writer initialization in QueueSubscriptions

- Simplified the initialization of user reader and writer instances in the QueueSubscriptions function by reusing the created userReaderWriter variable, enhancing code clarity and reducing redundancy.

Jira Ticket: https://linuxfoundation.atlassian.net/browse/LFXV2-492

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Signed-off-by: Mauricio Zanetti Salomao <mauriciozanetti86@gmail.com>

Author: mauriciozanettisalomao

cmd/server/service/providers.go

@@ -137,13 +137,15 @@ func QueueSubscriptions(ctx context.Context) error {
 	// Initialize NATS client first
 	natsInit(ctx)
 
+	userReaderWriter := newUserReaderWriter(ctx)
+
 	messageHandlerService := &MessageHandlerService{
 		messageHandler: service.NewMessageHandlerOrchestrator(
 			service.WithUserWriterForMessageHandler(
-				newUserReaderWriter(ctx),
+				userReaderWriter,
 			),
 			service.WithUserReaderForMessageHandler(
-				newUserReaderWriter(ctx),
+				userReaderWriter,
 			),
 		),
 	}