godot/scene/theme/icons/arrow_down.svg

<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16"><path fill="none" stroke="#b2b2b2" stroke-linecap="round" stroke-linejoin="round" stroke-opacity=".45" stroke-width="2" d="m5 7 3 3 3-3"/></svg>