It’s the crossover we’ve all been waiting for. It looks like the cast of the original “High School Musical” films and the cast of “High School Musical: The Musical: The Series” will be colliding in Season 4 of the Disney+ series.After spending the summer at camp, the Wildcats are returning to school for Season 4, only to find out that they’ll be featured extras in the long-awaited “High School Musical 4: The Reunion,” which is currently filming at their school.And speaking of the original films, the students of East High will be returning to their roots for their fourth musical.