Four-times Formula One world champion Sebastian Vettel will test for Porsche next week in Spain as the German carmaker gears up for the Le Mans 24-hour. Speculation is increasing that Vettel may race in the iconic French race this year and return to F1 at some point, with Germany’s Audi taking over Sauber. He left F1 in 2022 afte racing for Aston Martin. “I’ve always followed other racing series and my curiosity about endurance racing encouraged me to give it a try. Now I’m excited about the endurance race in Aragon and I’m looking forward to the time behind the wheel,” Vettel, 36, said in a s…