### 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.
if (owner) {
					Ref<SceneState> ss_inst = owner->get_scene_instance_state();
					if (ss_inst.is_valid()) {
						ss_inst->update_instance_resource(p_instance_path, current_packed_scene);
					}
					owner->set_editable_instance(instantiated_node, is_editable);
				}
				
				for (AdditiveNodeEntry additive_node_entry : addition_list) {
					Node *parent_node = instantiated_node->get_node_or_null(additive_node_entry.parent);
					if (!parent_node) {
						parent_node = current_edited_scene;
					}
					parent_node->add_child(additive_node_entry.node);
					parent_node->move_child(additive_node_entry.node, additive_node_entry.index);
					
					if (additive_node_entry.owner == original_node) {
						additive_node_entry.owner = instantiated_node;
					}
					additive_node_entry.node->set_owner(additive_node_entry.owner);
					
					{
						Node2D *node_2d = Object::cast_to<Node2D>(additive_node_entry.node);
						if (node_2d) {
							node_2d->set_transform(additive_node_entry.transform_2d);
						}
						Node3D *node_3d = Object::cast_to<Node3D>(additive_node_entry.node);
						if (node_3d) {
							node_3d->set_transform(additive_node_entry.transform_3d);
						}