Shares of Papa John's sank nearly 20% on Tuesday following a report that Apollo Global has withdrawn its offer to take the pizza chain private.Reuters reported that the private equity firm backtracked on its bid, valued at $64 a share, about a week ago. The firm previously submitted an offer for Papa John's alongside Irth Capital Management, according to Reuters.Apollo and Papa John's did not immediately respond to requests for comment.Papa John's is preparing to release its third-quarter earnings report on ...