The Sundance Film Festival’s lineups can often be dark affairs with edgy shocks, narcotics and strident political talking points. But one of the more soul-satisfying movies to premiere at the 2024 edition features no drug dealers, whistleblowers or bloodbaths. It’s about a sweet 93-year-old grandma played by June Squibb who collects marbles and rides a mobility scooter. And, OK, yes she also holds a man at gunpoint.