Use new extruderList rather than extruders

The extruders dictionary has been deprecated in favour of extruderList.

Done during Turbo Testing and Tooling to reduce the number of warnings in our log.

cura/Settings/CuraStackBuilder.py

@@ -62,7 +62,7 @@ class CuraStackBuilder:
             except IndexError:
                 return None
 
-        for new_extruder in new_global_stack.extruders.values():  # Only register the extruders if we're sure that all of them are correct.
+        for new_extruder in new_global_stack.extruderList:  # Only register the extruders if we're sure that all of them are correct.
             registry.addContainer(new_extruder)
 
         # Register the global stack after the extruder stacks are created. This prevents the registry from adding another