The `SCENE_OT_delete` and `SCENE_OT_view_layer_remove` operators did
not require any confirmation. Since the "New" and "Delete" buttons are
right next to each other, I think it would make sense to ask for
confirmation before deleting a scene or a view layer.
Note that this does not affect python scripts that call e.g.
```
>>> bpy.ops.scene.delete()
```