### 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 (err != OK) {
		show_accept(TTR("Couldn't save scene. Likely dependencies (instances or inheritance) couldn't be satisfied."), TTR("OK"));
		return;
	}
	int flg = 0;
	if (EDITOR_GET("filesystem/on_save/compress_binary_resources")) {
		flg |= ResourceSaver::FLAG_COMPRESS;
	}
	flg |= ResourceSaver::FLAG_REPLACE_SUBRESOURCE_PATHS;
	err = ResourceSaver::save(sdata, p_file, flg);
	
	emit_signal(SNAME("scene_saved"), p_file);
	_save_external_resources();
	editor_data.save_editor_external_data();
	for (Ref<AnimatedValuesBackup> &E : anim_backups) {
		E->restore();
	}
	if (err == OK) {
		scene->set_scene_file_path(ProjectSettings::get_singleton()->localize_path(p_file));
		editor_data.set_scene_as_saved(idx);
		editor_data.set_scene_modified_time(idx, FileAccess::get_modified_time(p_file));
		editor_folding.save_scene_folding(scene, p_file);
		_update_title();
		_update_scene_tabs();
	} else {
		_dialog_display_save_error(p_file, err);
	}
	scene->propagate_notification(NOTIFICATION_EDITOR_POST_SAVE);
}
void EditorNode::save_all_scenes() {