Sarah Snook is so adept at embodying the wily Siobhan “Shiv” Roy, on HBO’s breakout hit Succession, that she feels compelled to make clear that she is nothing like the character in real life. “I get a lot of ‘Shiv’s pretty badass,’ which I like, [but] I worry that people will think that I’m like Shiv … and I’m very different,” she explained in early August, shortly after finishing filming on Season Two. “She’s all buttoned up and straight lines, and I’m not that. I’m, hopefully, a lot…