Seven years into the “Stranger Things” franchise, and we still can’t get enough of Millie Bobby Brown and Noah Schnapp’s sweet friendship. The actors — who portray Eleven and Will Beyers on the Netflix series, respectively — have formed quite the unbeatable bond since meeting on set. While filming four seasons of the sci-fi show, they’ve evolved from mere costars to inseparable pals who love taking candid selfies, attending A-list events, goofing off on the red carpet, and celebrating…