The California marketing firm behind Bud Light’s disastrous tie-up with Dylan Mulvaney fired more than a dozen employees – days after top brass boasted about a lavish junket to an award ceremony on the French Riviera, The Post has learned. San Mateo-based Captiv8 — which The Post exclusively identified as the ad agency behind Anheuser-Busch’s short-lived partnership with the trans influencer — flew executives and guests on a private jet to the annual Cannes-Lions festival in June. Captiv8 booked the private charter on a boutique French airline called La Compagnie which features 76 lay-flat seats and a “bespoke plane experience,”...