SPRINGFIELD — A dismissed lawsuit challenging mandatory union dues in Illinois didn’t get a second chance this week after a federal appeals panel affirmed the trial judge’s order. It’s a dispute that could eventually find its way to the U.S. Supreme Court.The 7th U.S. Circuit Court of Appeals on Tuesday affirmed U.S. District Judge Robert W. Gettleman’s ruling, which dismissed claims that mandatory union dues for nonunion members violate those workers’ free speech protections.The case …