SceneTreeDock: Avoid changing the currently edited object when attaching a script

[garychia]

Fixes #81323

[KoBeWi]

tbh I sometimes rely on this behavior when I forget to name the script, but I get why it can be annoying.

btw Detach Script has the same problem, although there it's explicitly coded for some unexplained reason.

godot/editor/scene_tree_dock.cpp

Line 571 in f71f4b8

undo_redo->add_do_method(EditorNode::get_singleton(), "push_item", (Script *)nullptr);

[akien-mga]

btw Detach Script has the same problem, although there it's explicitly coded for some unexplained reason.

Should this be handled in this PR too?

[KoBeWi]

It can be done in this PR too, it's just one line removal.

The line ensures that the script does not stay in the inspector (which might make sense given the current attach behavior), not sure if it did anything else.

[akien-mga]

Let's merge this one for now as we're not sure whether the other removal would always be wanted.

[akien-mga]

Thanks!