I f it were any other show, the sight of the comedian Alan Carr sobbing under the burden of his dishonesty may have been enough to put off any celebrity thinking about accepting a place in the perilous Traitors’ castle. Yet the second season of The Celebrity Traitors, being filmed at its now famous Highlands retreat , has managed to attract one of the most high-profile casts ever assembled for a reality TV show. Actors who open West End shows and others with Oscar nominations to their name will be plotting alongside the nation’s most in-demand comedians and writers – and the odd fashion icon. The starry lineup was announced as filming began, amid speculation it would have been too hard to keep under wraps. “I think it might be the most impressive lineup ever recruited for a reality show in the UK,” said Peter Fincham, a former BBC One controller and co-presenter of the Insiders: The TV Podcast.…