Don't notify qml of update if no configurations changed

This might be the cause of #11608, but i'm not entirely sure. Whatever
the case, it's also not going to hurt checking this...

cura/PrinterOutput/Models/PrinterOutputModel.py

@@ -350,5 +350,6 @@ class PrinterOutputModel(QObject):
             self.availableConfigurationsChanged.emit()
 
     def setAvailableConfigurations(self, new_configurations: List[PrinterConfigurationModel]) -> None:
-        self._available_printer_configurations = new_configurations
-        self.availableConfigurationsChanged.emit()
+        if self._available_printer_configurations != new_configurations:
+            self._available_printer_configurations = new_configurations
+            self.availableConfigurationsChanged.emit()