accused of sexual misconduct, Zack Snyder made the decision to digitally replace his role in “Army of the Dead” with an unusual choice: Tig Notaro.Notaro had never done major stunt work before (she’s done some light action scenes on “Star Trek: Discovery”). But she found herself pretending she was piloting a helicopter while evading a zombie as well as learning how to handle a prop machine gun in Snyder’s film.