BERLIN — Senior German officials cast doubt Saturday on Turkey’s chances of joining the European Union, amid growing tensions with Ankara over human rights and Turkey’s claim that it’s being treated unfairly by countries in western Europe. In an interview published by Hamburg weekly Der Spiegel, Germany’s foreign minister suggested that for now the most that Turkey can hope for is to one day achieve a “privileged partnership” with the bloc. “Turkey is further away than ever before from EU membership,” Sigmar Gabriel was quoted as saying. Gabriel said he was always skeptical of the idea of Turkish EU membership.