Fix schema mismatch in ColumnPSetsOfSets.ifc test fixture

The fixture declared FILE_SCHEMA(('IFC2X3')) but used
IFCPROPERTYSETDEFINITIONSET(...), a defined type that only exists in
IFC4+ (confirmed absent from the generated Ifc2x3-schema.cpp/
Ifc2x3-definitions.h, present in the IFC4 equivalents). The file's own
FILE_NAME record ('Column_4x3.ifc') suggests it was originally
exported as IFC4X3 and the schema tag was later miscopied to IFC2X3.

Traced with an instrumented parser build: on encountering the
unrecognized keyword, declaration_by_name() correctly throws
"Entity with name 'IFCPROPERTYSETDEFINITIONSET' not found in schema
'IFC2X3'", caught by the existing IfcException handler in
in_memory_file_storage::load(). The parser then falls back to parsing
the trailing (#136,#138) as a plain nested SET rather than the typed
value, so RelatingPropertyDefinition ends up as a bare tuple instead
of an IfcPropertySetDefinitionSet-wrapped value with .is_a(). This is
correct, expected behavior for content that doesn't match its
declared schema - not a parser bug. Fixing the header to IFC4 (which
does declare the type) resolves test_stream, test_file, and test_rocks
in test_streaming_rocksdb_and_simpletyperefs.py.

Generated with the assistance of an AI coding tool.

src/ifcopenshell-python/test/fixtures/ColumnPSetsOfSets.ifc

@@ -2,7 +2,7 @@ ISO-10303-21;
 HEADER;
 FILE_DESCRIPTION(('ViewDefinition [CoordinationView]','RevitIdentifiers [ContentGUID: a0df3484-2dab-42c5-b806-8c10d313bee0, VersionGUID: 658c1394-f3a4-43d1-9b3c-eee44a0cd67a, NumberOfSaves: 2]','CoordinateReference [CoordinateBase: Shared Coordinates]'),'2;1');
 FILE_NAME('Column_4x3.ifc','2025-03-12T13:53:30+00:00',(''),(''),'ODA SDAI 24.12','Autodesk Revit 25.4.0.32 (ENG) - IFC 25.4.0.32','');
-FILE_SCHEMA(('IFC2X3'));
+FILE_SCHEMA(('IFC4'));
 ENDSEC;
 DATA;
 #1=IFCORGANIZATION($,'Autodesk Revit 2025 (ENG)',$,$,$);