Always implement getOwnEnumerablePropertyKeys

According to JSProxy.h, without this the default implementation calls
ownPropertyKeys and filters out the unenumerable properties. We know when such
things exist so we don't need to do that.

components/script/dom/bindings/codegen/CodegenRust.py

@@ -2602,9 +2602,9 @@ class CGDefineProxyHandler(CGAbstractMethod):
         if self.descriptor.operations['NamedDeleter']:
             customDelete = 'delete'
 
-        getOwnEnumerablePropertyKeys = "None"
+        getOwnEnumerablePropertyKeys = "own_property_keys"
         if self.descriptor.interface.getExtendedAttribute("LegacyUnenumerableNamedProperties"):
-            getOwnEnumerablePropertyKeys = "Some(getOwnEnumerablePropertyKeys)"
+            getOwnEnumerablePropertyKeys = "getOwnEnumerablePropertyKeys"
 
         args = {
             "defineProperty": customDefineProperty,
@@ -2631,7 +2631,7 @@ let traps = ProxyTraps {
     construct: None,
     getPropertyDescriptor: Some(get_property_descriptor),
     hasOwn: Some(hasOwn),
-    getOwnEnumerablePropertyKeys: %(getOwnEnumerablePropertyKeys)s,
+    getOwnEnumerablePropertyKeys: Some(%(getOwnEnumerablePropertyKeys)s),
     nativeCall: None,
     hasInstance: None,
     objectClassIs: None,