### 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.
}
						
						for (const Connection &E2 : E.value.connections_from) {
							Connection conn = E2;
							bool valid = modifiable_node->has_method(conn.callable.get_method()) || Ref<Script>(modifiable_node->get_script()).is_null() || Ref<Script>(modifiable_node->get_script())->has_method(conn.callable.get_method());
							ERR_CONTINUE_MSG(!valid, vformat("Attempt to connect signal '%s.%s' to nonexistent method '%s.%s'.", conn.signal.get_object()->get_class(), conn.signal.get_name(), conn.callable.get_object()->get_class(), conn.callable.get_method()));
							
							Object *source_object = conn.signal.get_object();
							if (source_object) {
								ERR_FAIL_COND(source_object->connect(conn.signal.get_name(), Callable(modifiable_node, conn.callable.get_method()), conn.flags) != OK);
							}
						}
						
						for (const Node::GroupInfo &E2 : E.value.groups) {
							modifiable_node->add_to_group(E2.name, E2.persistent);
						}
					}
				}
			}
			
			editor_history.cleanup_history();
			current_edited_scene->propagate_notification(NOTIFICATION_NODE_RECACHE_REQUESTED);
		}
		edited_scene_map.clear();
	}
	editor_data.set_edited_scene(original_edited_scene_idx);
	_edit_current();
}
int EditorNode::plugin_init_callback_count = 0;
void EditorNode::add_plugin_init_callback(EditorPluginInitializeCallback p_callback) {