Rebecca Rubin Film and Media ReporterWriter Simon Rich, who counts Seth Rogen (for “An American Pickle”) and Lorne Michaels (for “Miracle Workers” and “Man Seeking Woman”) among his collaborators and Seth Meyers and John Mulaney among his friends, hasn’t had trouble staying productive during the pandemic.“It’s much easier to be a fiction writer than a feature director right now,” he observes.The rest of the world may be filled with existential dread, but Rich, whose resume includes “Saturday