The third season of Yellowjackets is a bit like getting lured back to the high school reunion that was delightfully fun the first time but eventually becomes an exercise in diminishing returns. Maybe it’s part of our soft human inability to let go of the past, especially coming-of-age drama that seems increasingly romantic and valid as we continue hurtling toward old age and (hopefully) painless deaths. Maybe it’s the misplaced optimism that middle-aged reunions will evoke some kind of sobering epiphany about lost youth or, god forbid, a painful…