Libyan rebels Monday during an attack on Surt, one of the last strongholds of Qaddafi support.Credit...Manu Brabo/Associated Press TRIPOLI, Libya — Libya’s provisional leaders said Monday that they would resign once the former rebels defeat the vestiges of armed support for Col. Muammar el-Qaddafi in his home city of Surt, a move that would clear the way for a new interim government that would run