FALLS CHURCH, Va. — The U.S. Supreme Court won’t hear an appeal from a Virginia school board that says it shouldn’t be held liable for the alleged sexual assault of a student by a classmate on a band trip.The court without comment on Monday rejected the appeal from the Fairfax County School Board. The case will now go to trial in federal court in Alexandria, Virginia.The case turned on whether a school system can be held liable under Title IX for a single alleged assault when there had been no prior …