Removes duplicate prefix when calling getNidsOfType

I updated the code to prevent a duplicate "item_item_" string in the log.

Testing

1. Add a custom script in your my_module/src/cbo_scripts folder.
2. In the custom script, using the getNidsOfType() method inside the gatherItemsToProcess() method.
3. Run your script.
4. Confirm that each log row starts with "item_{nid}".