CMT announced another round of performers and entertainers for its two-hour TV special, CMT Celebrates Our Heroes: An Artists of the Year Special, on June 3 at 7 p.m. CT. Blake Shelton, Gary Sinise, Jake Owen, Jason Aldean, Keith Urban, Lee Brice, Olivia Munn, Reba McEntire, Scarlett Johansson, Sean Penn, Bobby Bones, Cody Alan and…