### 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.
EditorInspector::cleanup_plugins();
	EditorTranslationParser::get_singleton()->clean_parsers();
	ResourceImporterScene::clean_up_importer_plugins();
	remove_print_handler(&print_handler);
	EditorHelp::cleanup_doc();
	memdelete(editor_selection);
	memdelete(editor_plugins_over);
	memdelete(editor_plugins_force_over);
	memdelete(editor_plugins_force_input_forwarding);
	memdelete(progress_hb);
	EditorSettings::destroy();
}
/*
 * EDITOR PLUGIN LIST
 */
void EditorPluginList::make_visible(bool p_visible) {