WASHINGTON — The food industry is pressuring Congress to act before the state of Vermont requires food labels for genetically modified ingredients.At issue is how food companies will deal with Vermont’s law. They could make separate food packages just for the state, label all their items with genetically modified ingredients or withdraw from the small Vermont market. The law kicks in by July, but the companies have to start making those decisions now.The food industry wants Congress to pre-empt Vermont’s law and bar …