### 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.
exiting = true;
	resource_preview->stop(); 
	_save_editor_layout();
	
	dim_editor(true);
	get_tree()->quit(p_exit_code);
}
void EditorNode::_discard_changes(const String &p_str) {
	switch (current_menu_option) {
		case FILE_CLOSE:
		case SCENE_TAB_CLOSE: {
			Node *scene = editor_data.get_edited_scene_root(tab_closing_idx);
			if (scene != nullptr) {
				String scene_filename = scene->get_scene_file_path();
				if (!scene_filename.is_empty()) {
					previous_scenes.push_back(scene_filename);
				}
			}
			
			if (!_is_closing_editor()) {
				_remove_scene(tab_closing_idx);
				_update_scene_tabs();