The governor of the Public Investment Fund, Saudi Arabia’s $620-billion sovereign wealth fund, will not testify in defense of Elon Musk in an upcoming trial brought by Tesla investors alleging Musk defrauded them with the 2018 tweet that funding for taking the EV maker private is “secured.” Last week, lawyers for Musk tried to subpoena Yasir Al-Rumayyan, the governor of the Public Investment Fund (PIF), to force him to testify in the trial slated to begin in San Francisco on January 17. Investors in Tesla are suing Musk…