By Lucia Mutikani WASHINGTON (Reuters) – U.S. retail sales fell by the most in a year in December, pulled down by declines in purchases of motor vehicles and a range of other goods, putting consumer spending and the overall economy on a weaker growth path heading into 2023. The second straight monthly decrease in retail sales, which are mostly goods, is undercutting production at factories. Manufacturing output recorded its biggest drop in nearly two years in December, while monthly producer prices also tumbled, other data showed on Wednesday. The widespread signs of weakening demand and subsi…