Bloomberg's @markgurman says that even though Apple partnered with Google Gemini for Siri, they actually run their business on Anthropic. "Apple runs on Anthropic at this point. Anthropic is powering a lot of the stuff Apple's doing internally in terms of product development and a lot of their internal tools." "They have custom versions of Claude running on their own servers internally, too. This Google deal just came together a few months ago. They were not going to use Google. Apple…