Philadelphia, Pennsylvania — The Philadelphia 76ers have decided not to build a $1.3 billion downtown arena, a surprising move that comes just weeks after the team received approval for the controversial project from the city council. The Philadelphia Inquirer reported Sunday that multiple council members had confirmed the change in plans. The team has struck a deal with Comcast Spectacor to remain in the city’s sports stadium district, the newspaper said, but further details about the new proposal have not been released. The 76ers, the mayor’s office and Comcast Spectacor — which owns the Wells Fargo Center, where the team