ARLINGTON, Va. — Air Force 2nd Lt. Jacob Bradosky cruised across the National Mall and streaked into the lead at the infamous 20-mile marker to win the Marine Corps Marathon in 2 hours 23 minutes and 30 seconds, giving airmen a reason to brag come Monday morning at joint bases across the Defense Department. Bradosky beat a field of 30,000 racers that included 4,385 active duty service members on an unseasonably warm Halloween morning in the National Capital region. Janet Cherobon, a Kenya native who is studying for American citizenship, won the women’s division in 2:39:16. Navy Lt. Gina Slaby,…