Paris  —  When guests arrived for the Balenciaga show during Paris Fashion Week on Saturday evening, several found themselves on familiar ground: a chapel built during the reign of the former French King Louis XIII, which is part of the historic Laennec headquarters of Balenciaga’s owner, Kering. After all, it was only three months ago that a retrospective for the brand’s former designer, Demna (now at Gucci), took place here. For Pierpaolo Piccioli, the creative director of the Paris-based