A federal appeals court has declined to temporarily halt enforcement of a Chicago ordinance that bars texting while driving.The 7th U.S. Circuit Court of Appeals this week did not rule on the merits of Tamara Simic’s contention that the ordinance runs afoul of the U.S. Constitution.But the court upheld a decision by U.S. District Judge Sharon Johnson Coleman to deny Simic’s motion for a preliminary injunction.A panel of the court agreed with Coleman that Simic has not shown she faced the threat of irreparable …