Liv Tyler is one proud mom. The actress, 45, celebrated a special moment as her oldest, 18-year-old son Milo, graduated high school, sharing photos on Instagram early Friday. “This happened ????‍???? what a journey !! so SO soooo proud of you Milo ????,” she captioned a set of photos that show the teen throughout the ceremony. https://www.instagram.com/p/CuHTi3eLoQk/?utm_source=ig_embed&ig_rid=a6eb90b4-e347-4dd0-8644-0693defb460e In another post, …