Who you gonna call for a new version of the kids science show “Magic School Bus”? Kate McKinnon, that’s who. Already famed for her “Saturday Night Live” alter egos Olya Povlatsky, Sheila Sovage and Les Dykawitz — as well as her “Ghostbusters” turn as Dr. Jillian “Holtz” Holtzmann — the Emmy winner will voice Ms. […]