MINNEAPOLIS — Rep. Ilhan Omar’s marriage appears to be headed for the rocks, a longtime friend of the couple told The Post. The congresswoman’s husband, Ahmed Hirsi, the source said, is poised to file for divorce after the revelation in a bombshell court filing that she allegedly had an affair with DC political consultant Tim Mynett. The Minnesota congresswoman and her husband allegedly separated in March, and Omar asked Hirsi to divorce her around that time because she didn’t want to file the papers — but Hirsi refused, telling her if she wanted a divorce she should do it herself,...