Nvidia’s board is preparing to oust CEO Jensen Huang after he had two extramarital affairs, including one with a suspected Chinese spy and another with an employee. The board was planning to meet as soon as Wednesday night (US time) to determine his future, people familiar with the matter said. His departure would bring down the curtain on an era during which he stoked the global artificial-intelligence boom and became a geopolitical star. It would leave one of the world’s most valuable companies in need of a new leader. Huang, a co-founder of Nvidia, is seen by many as the…