By Hunter Hodies One of the best play-by-play announcers on the planet won’t be calling NFL games this fall. Gus Johnson won’t be able to call those games due to a lack of availability. He spoke on Richard Deitsch’s podcast about how he’s part of Harvard’s Advanced Leadership Initiative, which will cut down on his workload. “I don’t think I’m going to be able to do the NFL this year, Rich because I went back to school,” Johnson said. “I’m back in college now. And my classes are on Mondays, Wednesdays, and Thursdays. So I’m probably going to need to call the college games on Saturday, and it’s …