By Daniel Bird The Great British Bake Off’s Prue Leith has become embroiled in a heated war of words with a former co-star. The cookery writer and presenter has appeared on the programme since March 2017 having replaced Mary Berry when the show moved to Channel 4. Since joining, she’s seen a string of co-stars exit the show, with many often praising the baking competition which is filmed in a sprawling gazebo tent. But former presenter Sandi Toksvig \- who stepped down as a presenter in 2020 – has previously hit out at the show and branded it “boring”, which Prue has taken offence to. Prue, 83…