By Saqib Iqbal Ahmed NEW YORK (Reuters) -The U.S. dollar fell across the board on Thursday, ceding ground gained in recent sessions as firmer risk sentiment prompted investors to reach for higher-yielding currencies. Stock markets around the world rose on Thursday after recent weakness, as bets Saudi Arabia may boost crude production cooled oil prices, helping balance concerns over surging inflation and monetary policy tightening. “There are a few factors working against the greenback today, but it’s mostly risk-on sentiment,” said John Doyle, vice president of dealing and trading at Monex USA…