Dolly Parton has died at the age of 80, and her nephew Bryan Seaver shared a heartfelt video informing fans of the sad news Tuesday. “Hey everyone, my name is Bryan Seaver, son of Cassie Parton, and I am representing the Parton and Owens family today, announcing the passing of my Aunt Dolly Rebecca Parton Dean — sister, sis, aunt, granny to one generation and Gigi to the next.” “This video announcement is something Dolly asked of me years ago before I fully absorbed it as a future reality,” he continued. “As her head of security, for more than two decades, a role my father Larry held before me. I have imagined the heaviness of this…