Fix #3614. Remove_pset API now supports removing predefined property sets (E.g. door lining properties).

src/ifcopenshell-python/ifcopenshell/api/pset/remove_pset.py

@@ -57,6 +57,7 @@ class Usecase:
                     inverse.RelatedObjects = related_objects
                     should_remove_pset = False
         if should_remove_pset:
+            properties = []  # Predefined psets have no properties
             if self.settings["pset"].is_a("IfcPropertySet"):
                 properties = self.settings["pset"].HasProperties or []
             elif self.settings["pset"].is_a("IfcQuantitySet"):