Home Box Office has picked up the hit series “The Larry Sanders Show,” starring Garry Shandling, for 22 additional episodes next season.The pay-cabler’s decision is not surprising, given the critical raves and solid ratings the show’s received. New episodes of the series, in which Shandling stars as a late-night talkshow host, will start production in early 1993. In its first season, the show has featured appearances, as themselves, by celebs including Carol Burnett, Dana Carvey, Billy Crystal and Robin Williams. Next year, the series will continue its course, said senior VP of original programming Bridget Potter. “We want to attract a level of performance that’s about as sophisticated as it can be about our business,” she said.