Former Formula One world champion Sebastian Vettel has left it open whether he would come out of retirement and join the Mercedes team join next year as successor of Lewis Hamilton. Vettel told Friday’s Neue Zürcher Zeitung he was surprised just like many others when seven-time champion Hamilton announced in January he would leave Mercedes after 12 years to drive for Ferrari from 2025. “Mercedes team principal Toto Wolff did not phone me up but we exchanged a few text messages. But this is not an issue for me right now because at 36 I have all the time in the world. That is not going away.” Ge…