WASHINGTON — The U.S. Postal Service announced Thursday it ordered more than 10,000 new electric delivery trucks, up from the 5,000 the agency had initially planned to purchase. It’s part of the service’s initial $2.98 billion order of 50,000 new delivery vehicles from Oshkosh Corp. as part of a contract to replace its 30-year-old fleet. Postmaster General Louis DeJoy said in a statement that the agency has been evaluating its financial outlook and the potential use of EVs over the last year and a half. “Based upon this work and our improving outlook, we have determined that increasing our ini…