bug: GUI-Editor use deprecated size of ha-button

GUI Editor shows console message: `[ha-button] size="small" is deprecated. Use size="s" instead. The long-form value will be removed in the next major version.` See: https://github.com/search?q=repo%3AMelleD%2Flovelace-expander-card%20size%3D%22small%22&type=code