Apple Inc. is in early discussions about using Google Gemini to power a revamped version of the Siri voice assistant, marking a key potential step toward outsourcing more of its artificial intelligence technology. The iPhone maker recently approached Alphabet Inc.’s Google to explore building a custom AI model that would serve as the foundation of the new Siri next year, according to people familiar with he matter. Google has started training a model that could run on Apple’s servers, said the p...