### 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.
case HELP_COMMUNITY: {
			OS::get_singleton()->shell_open("https:godotengine.org/community");
		} break;
		case HELP_ABOUT: {
			about->popup_centered(Size2(780, 500) * EDSCALE);
		} break;
		case HELP_SUPPORT_GODOT_DEVELOPMENT: {
			OS::get_singleton()->shell_open("https:godotengine.org/donate");
		} break;
		case SET_RENDERER_NAME_SAVE_AND_RESTART: {
			ProjectSettings::get_singleton()->set("rendering/renderer/rendering_method", renderer_request);
			ProjectSettings::get_singleton()->save();
			save_all_scenes();
			restart_editor();
		} break;
	}
}
String EditorNode::adjust_scene_name_casing(const String &root_name) {
	switch (GLOBAL_GET("editor/naming/scene_name_casing").operator int()) {
		case SCENE_NAME_CASING_AUTO:
			
			break;
		case SCENE_NAME_CASING_PASCAL_CASE:
			return root_name.to_pascal_case();
		case SCENE_NAME_CASING_SNAKE_CASE:
			return root_name.replace("-", "_").to_snake_case();
	}
	return root_name;
}
void EditorNode::_request_screenshot() {