It’s getting more expensive to eat out.Full-service restaurants, facing higher labor and food costs, raised prices the most in more than seven years in December, a U.S. Labor Department report released Friday shows. As grocery costs rise at a slower pace, that could push more U.S. consumers to eat at home, potentially shifting sales away from sit-down chains.The gap between how much it costs to eat out instead of grocery shopping “has continued to widen pretty aggressively.