By Saqib Iqbal Ahmed and Chuck Mikolajczak NEW YORK (Reuters) – The dollar dipped modestly against a basket of currencies on Monday but remained near a 21-month high hit last week as investors eyed Russia-Ukraine peace talks, while major central bank meetings this week kept large moves in foreign exchange in check. The dollar index fell 0.056% at 98.96, not far from the 99.415 touched a week ago, the highest level for the greenback since May 2020. Tentative hopes of progress in peace talks between Ukraine and Russia helped boost the appetite for riskier currencies on Monday, though upcoming ce…