Not to be dramatic, but Scarlett Johansson found the most timeless wardrobe staple. Instead of a tight tank, she wore flowy knit version, and it screamed ‘old money.’ We uncovered Johansson’s classy look on Amazon . . . and it also happens to be on sale for $15. In an Instagram Reel for The Outset, Johansson had a .02-second blip showcasing one of the brand’s beauty products. That was all we needed to see her chic tank style, and honestly, it mi…