*****FLYING SAUCER-SIZED SPOILERS!***** Writer-director Brian Duffield has crafted a few sci-fi/horror movies where a protagonist is left to their own resources to deal with with a cataclysm or conspiracy (“Love and Monsters” “The Babysitter”).  That template is used once again with his latest movie, “No One Will Save You,” which stars Kaitlyn Dever (“Last Man…