OpenAI has hired Sarah Friar, the former chief executive of neighborhood social networking service Nextdoor Holdings Inc., to serve as its chief financial officer, a role that has gone unfilled at the fast-growing artificial intelligence startup for two years. The ChatGPT maker has also named Kevin Weil as its new chief product officer, the company is set to announce Monday. Weil previously steered product development at Instagram and Twitter as an executive at those companies.The expanded C-Su...