Marvel's long-awaited Black Widow movie gets more exciting with each new casting announcement and this is the best one yet. The latest casting news brings The Favourite star Rachel Weisz and Stranger Things breakout David Harbour into the superspy equation. The duo is poised to join Scarlett Johansson and rising star Florence Pugh (Fighting with My Family) in the standalone film. Weisz is coming off a well-deserved Oscar nomination for her scene-stealing turn in The Favourite and Variety brings the news that she's in early talks to join the MCU. The report notes that the …