### 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.
Node *scene = editor_data.get_edited_scene_root(scene_idx);
			if (scene && !scene->get_scene_file_path().is_empty()) {
				if (DirAccess::exists(scene->get_scene_file_path().get_base_dir())) {
					if (scene_idx != editor_data.get_edited_scene()) {
						_save_scene_with_preview(scene->get_scene_file_path(), scene_idx);
					} else {
						_save_scene_with_preview(scene->get_scene_file_path());
					}
					if (scene_idx != -1) {
						_discard_changes();
					}
					save_editor_layout_delayed();
				} else {
					show_save_accept(vformat(TTR("%s no longer exists! Please specify a new save location."), scene->get_scene_file_path().get_base_dir()), TTR("OK"));
				}
				break;
			}
			[[fallthrough]];
		}
		case FILE_SAVE_AS_SCENE: {
			int scene_idx = (p_option == FILE_SAVE_SCENE || p_option == FILE_SAVE_AS_SCENE) ? -1 : tab_closing_idx;
			Node *scene = editor_data.get_edited_scene_root(scene_idx);
			if (!scene) {
				if (p_option == FILE_SAVE_SCENE) {
					
					
					ScriptEditor::get_singleton()->save_current_script();
				}
				const int saved = _save_external_resources();
				if (saved > 0) {