Darren Smith was walking out of the Merrion shopping centre in Dublin when he got a call from RTÉ. No, the broadcaster told him; The Traitors isn’t going to work, “it’s not for us”. Smith, the founder and managing director of Kite Entertainment, called Mairéad Whelan, Kite’s director of content, to break the news. “Well, they’re wrong,” she told him. And so it proved to be.  The production company that Smith set up in 2004 is behind one of the most anticipated television shows this year. Filming on the series wrapped in Slane Castle in April, with Siobhán McSweeney hosting.…