A new lawsuit is challenging a decision by the administration of Gov. Mike Dunleavy that emptied Alaska’s $410 million higher-education trust fund last year, eliminating a reliable source of funding for college scholarships and the state’s equivalent of medical school. On Tuesday, four university students filed suit against Dunleavy and two state agencies in Anchorage Superior Court, seeking to reverse the decision. The plaintiffs asked for summary judgment, which could move the case speedily through the courts.