A University of California Berkeley professor has been living in his office for a week as part of a sleep-in protest against the school administration for not doing enough to stop antisemitism and protect free speech on campus. Prof. Ron Hassner, a political science professor at Berkeley for the past 20 years, has been sleeping on a mattress beside his desk in the university’s Social Sciences Building since March 7. He told The Post he’ll hold out “as long as it takes” until UC Berkeley leadership addresses rampant antisemitism on campus — following an incident last month when a violent...