PHILADELPHIA — University of Pennsylvania president Liz Magill has resigned amid growing bipartisan backlash against her congressional committee testimony on antisemitism earlier this week and a semester marked by near-weekly protests, complaints by deep-pocketed donors, and widespread accusations of mismanagement since a controversial literary festival on campus this fall. And minutes later, Scott L. Bok, chair of the board of trustees, announced he was stepping down, too. “It has been my privilege to serve as president of this remarkable institution,” Magill said in a statement shared by Bok…