The Gyllenhaals are shoring up on HBO. Maggie Gyllenhaal anchors the pay cable network’s terrific drama The Deuce, which premieres its third and final season later this year, and now word comes that her brother Jake Gyllenhaal is heading to the not-TV network. Per THR, Jake Gyllenhaal will star in and executive produce a limited series adaptation of the Gary Shteyngart book Lake Success. Per HBO, the drama revolves around Barry Cohen (Gyllenhaal), “a narcissistic, self-deluded and hilariously divorced from the real-world hedge fund manager who flees his family, his past and the SEC on a …