`set_active_node` call from `grease_pencil_copy_data` resets inactive
layer again as locked before executing the drawing code. Since property
is only operated on layers, it is possible to remove the code from
`set_active_node()` and only have it in `set_active_layer()`.
Pull Request: https://projects.blender.org/blender/blender/pulls/129465
6cdac7bab8