On Friday, JetBlue Airways Corporation (NASDAQ:JBLU) and Spirit Airlines Inc. (NYSE:SAVE)confirmed they’re challenging a federal judge’s decision that prevents their proposed merger on grounds of antitrust. What Happened: JetBlue’s initial plan was to buy Spirit for $3.8 billion, as agreed in 2022. However, this plan was halted by a federal judge on Tuesday, arguing that the merger would lead to the elimination of the budget airline and result in higher prices for cost-conscious customers. Following the announcement of the appeal, Spirit’s shares soared over 10% in after-hours trading on Frida…