Enough time has passed for Greta Lee to open up about her fight to get cast in “Past Lives” — and that includes a “humiliating” experience that involved megaproducer Scott Rudin and “Barbie” filmmaker Greta Gerwig. In Monday’s episode of the “Conan O’Brien Needs a Friend” podcast, the host asked Lee about her touch-and-go experience with Celine Song’s “Past Lives” script early on and how she initially missed out on the role. “I think enough time…