(Reuters) – The U.S. Environmental Protection Agency (EPA) issued an emergency air-quality waiver through June 6 to boost supplies of gasoline in East Texas after production was cut at a regional refinery. The waiver allows the sale in 34 Texas counties of higher-volatility, winter-grade gasoline. The Biden administration has released emergency oil stocks and is considering lifting smog rules nationwide to combat rising fuel prices. Waivers typically are issued after hurricanes or other disasters that broadly cut fuel supplies and not for outages at a single refinery as in the Texas case. The …