Izzy Fairthorne said the entire cast of “The Challenge” Season 42 were “in shock” over Josh Goldstein, Leo Dionicio and Nelson Thomas’ triple disqualification — which was caused by an alleged racial incident that was cut from the edit. “We didn’t really know much about it. None of us were there,” Fairthorne exclusively told Page Six on Wednesday. “So when [host] T.J. [Lavin] came in and said, ‘They’re going,’ we were like, ‘What’s going on?’ They didn’t show it, but obviously we were so upset.” On the latest episode of “The Challenge: Cutthroat,” Lavin, 49, told the cast that Goldstein, Dionicio and Thomas “all broke the code of conduct”…