Prestigious universities across California are shelling out millions of dollars on artificial intelligence tools like ChatGPT for students — even as they lay off professors, The Post has learned. The prestigious University of Southern California, a private research college, spent $3.1 million in late January on a partnership with OpenAI to secure ChatGPT licenses for 80,000 users, including pupils, faculty and staff.  But professors at private USC, where one year of tuition costs nearly $80,000,