Refresh list of intents upon changing category

The category is changed after constructing by the QML code in order to set its property.
This is now updating twice: Once for the default category and once for the final one set by QML. This is a bit inefficient. But make it work before optimising it!

Contributes to issue CURA-6597.

cura/Machines/Models/IntentModel.py

@@ -33,6 +33,7 @@ class IntentModel(ListModel):
         if self._intent_category != new_category:
             self._intent_category = new_category
             self._intent_category_changed.emit()
+            self._update()
 
     @pyqtProperty(str, fset = setIntentCategory, notify = _intent_category_changed)
     def intentCategory(self) -> str: