### Godot version

4.1.beta (7b1387ff2)

### System information

Mageia 9, Linux

### Issue description

When opening an empty project in latest `master`, I get these errors:
```
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: get_scene_path (editor/scu/../editor_data.cpp:880)
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: check_and_update_scene (editor/scu/../editor_data.cpp:683)
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: set_edited_scene (editor/scu/../editor_data.cpp:745)
```

Possibly related to recent changes to restore past sessions, but there's nothing to restore in this case?

### Steps to reproduce

- Create a new project, edit it
- Quit to project manager
- Re-open the newly created project -> errors

### Minimal reproduction project

Empty project.
return changing_scene;
}
void EditorNode::set_current_scene(int p_idx) {
	
	if (editor_data.get_scene_path(p_idx) != "" && editor_data.get_edited_scene_root(p_idx)) {
		editor_folding.save_scene_folding(editor_data.get_edited_scene_root(p_idx), editor_data.get_scene_path(p_idx));
	}
	if (editor_data.check_and_update_scene(p_idx)) {
		if (editor_data.get_scene_path(p_idx) != "") {
			editor_folding.load_scene_folding(editor_data.get_edited_scene_root(p_idx), editor_data.get_scene_path(p_idx));
		}
		EditorUndoRedoManager::get_singleton()->clear_history(false, editor_data.get_scene_history_id(p_idx));
	}
	changing_scene = true;
	editor_data.save_edited_scene_state(editor_selection, &editor_history, _get_main_scene_state());
	if (get_editor_data().get_edited_scene_root()) {
		if (get_editor_data().get_edited_scene_root()->get_parent() == scene_root) {
			scene_root->remove_child(get_editor_data().get_edited_scene_root());
		}