### 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.
EditorFileSystemDirectory *efsd = EditorFileSystem::get_singleton()->get_filesystem_path(p_path.get_base_dir());
	if (efsd) {
		String file = p_path.get_file();
		for (int i = 0; i < efsd->get_file_count(); i++) {
			if (efsd->get_file(i) == file) {
				String type = efsd->get_file_type(i);
				if (singleton->icon_type_cache.has(type)) {
					return singleton->icon_type_cache[type];
				} else {
					return singleton->icon_type_cache["Object"];
				}
			}
		}
	}
	return singleton->icon_type_cache["Object"];
}
void EditorNode::_build_icon_type_cache() {