Implement forward compatibility for World by always writing `use_nodes=true` when saving blend files. This was missed in #142342 Pull Request: https://projects.blender.org/blender/blender/pulls/146628
Implement forward compatibility for World by always writing `use_nodes=true` when saving blend files. This was missed in #142342 Pull Request: https://projects.blender.org/blender/blender/pulls/146628