Fix: GPv3: Crash in realize instances node

This was reported by the studio. When opening one of the lighting
files in 4.3, Blender would crash.

The realize instance task for grease pencil needs to copy all the
layer attributes to the target geometry. When creating the
`dst_attribute_writers` using `lookup_or_add_for_write_only_span`
the `bke::AttrDomain::Point` was used when it should have been
`bke::AttrDomain::Layer`.

Pull Request: https://projects.blender.org/blender/blender/pulls/125603

source/blender/geometry/intern/realize_instances.cc

@@ -2119,7 +2119,7 @@ static void execute_realize_grease_pencil_tasks(
     const AttributeIDRef &attribute_id = ordered_attributes.ids[attribute_index];
     const eCustomDataType data_type = ordered_attributes.kinds[attribute_index].data_type;
     dst_attribute_writers.append(dst_attributes.lookup_or_add_for_write_only_span(
-        attribute_id, bke::AttrDomain::Point, data_type));
+        attribute_id, bke::AttrDomain::Layer, data_type));
   }
 
   /* Actually execute all tasks. */