He’s no Tofu Talarico — but he’s got a tofu-loving girlfriend. Texas Democratic Senate candidate James Talarico’s mysterious beau is a vegan political lobbyist who previously worked as his chief of staff, The Post has learned. Brianna Menard, 30, describes herself as a “committed vegan,” yoga buff and cat mom who likes “dancing the night away” at local gay bar Cheer Up Charlies in Austin, according her bio at a local food coop , where she serves on the board. “James is not and never has been a