Rain AI, a San Francisco-based startup backed by OpenAI co-founder Sam Altman, has appointed a former Apple Inc. chip executive to head its hardware engineering division. The new hire is expected to play a crucial role in the company’s quest to develop innovative semiconductors for artificial intelligence. What Happened: Rain AI has named Jean-Didier Allegrucci as the head of hardware engineering, reported Bloomberg on Friday. Allegrucci, who previously contributed to the development of processors that replaced Intel Corp. in iPhones and Macs, will lead the startup’s efforts to create more ene…