NEW YORK — Megan Thee Stallion is ready for double duty on “Saturday Night Live.” The Grammy-winning rapper will host and perform as the musical guest on the Oct. 15 episode of the sketch comedy series, NBC announced Tuesday in a larger reveal of its upcoming guests. Miles Teller will host the show’s Season 48 premiere on Oct. 1, with Kendrick Lamar named that episode’s musical guest. Emmy-winning actor Brendan Gleeson will then handle hosting duties on Oct. 8, with Willow Smith — daughter of Will Smith and Jada Pinkett Smith — performing the music. “OCT 15 THEE HOT GIRL COACH IS HOSTING AND P…