Ashley Tisdale’s BFF is getting in some time with her baby girl. Over the weekend, the High School Musical actress, 38, shared a photo of her daughter, 2-year-old Jupiter Iris, in the pool having fun with her longtime best friend and Sharpay’s Fabulous Adventure costar, Austin Butler. “Spent the day with Uncle Austin @austinbutler❤️,” Tisdale captioned the shot. The longtime …