rules fixture: nornallize headers

- to avoid some diffs on regeneration
- some fixtures had problems with the header, so `fail` for them wasn't
really testing the intended case, because small issues in the header
would make fixture fail regardless

src/ifcopenshell-python/test/fixtures/rules/generate_06.py

@@ -2,6 +2,7 @@ import itertools
 import time
 
 import ifcopenshell
+from generate import normalize_header
 
 for pty, ety in itertools.product(("GRILLE", "USERDEFINED"), (None, "Something")):
     f = ifcopenshell.file(schema="IFC2X3")
@@ -12,4 +13,5 @@ for pty, ety in itertools.product(("GRILLE", "USERDEFINED"), (None, "Something")
     ownerhist = f.createIfcOwnerHistory(pando, appl, ChangeAction="ADDED", CreationDate=int(time.time()))
     f.createIfcAirTerminalType(ifcopenshell.guid.new(), ownerhist, "My Type", ElementType=ety, PredefinedType=pty)
     valid = pty != "USERDEFINED" or ety is not None
+    normalize_header(f)
     f.write(f"{'pass' if valid else 'fail'}-air-terminal-type-{pty}-{ety}-ifc2x3.ifc")