Carey Mulligan deserves an Oscar nomination as a femme fatale striking fear in the hearts of men in “Promising Young Woman”. Cassie (Mulligan) is a vigilante of sorts, as she frequently pretends to be inebriated in local watering holes, dance clubs, and Irish bars. She then terrifies her aggressors when they overstep their bounds. Director/writer Emerald Fennell’s sobering – but also playful – screenplay takes dark turns and steers into some levity with Bo Burnham’s breezy, accessible arc. Ryan (Burnham) could be the male outlier to melt Cassie’s heart, as…