NEW YORK — Jessica Pegula is one win away from the US Open title. The American came roaring back from an early deficit to defeat Karolina Muchova — 1-6, 6-4, 6-2 — in her semifinal match at Arthur Ashe Stadium on Thursday night, booking her spot in Saturday’s women’s singles final. It’s the first trip to a Grand Slam final for Pegula, who will face Aryna Sabalenka after the Belarusian star …