NEW YORK — Iva Jovic, a 16-year-old from California, became the youngest American to win a women’s main-draw match at the U.S. Open since 2000, eliminating 2023 Australian Open semifinalist Magda Linette of Poland 6-4, 6-3 on Monday. “Surprised, but not surprised,” Jovic said about the result against someone who’s been ranked in the top 20. “I just had a …