Elon Musk is not joining Twitter’s board of directors, the social media company’s chief executive Parag Agrawal said Sunday evening. “Elon has decided not to join our board,” Agrawal tweeted. “Elon’s appointment to the board was to become officially effective 4/9, but Elon shared that same morning that he will no longer be joining the board. I believe that us for the best,” the Twitter CEO said in a “note to the company” which he shared on the social media platform. Twitter remained opened to Musk’s input, Agrawal added. Last week it was revealed that Tesla boss Musk had bought up more than 9%…