It’s been less than four months since Princess Beatrice’s ex-boyfriend was found dead in a Miami hotel room, and now we know what killed him. Paolo Liuzzodied from an overdose after consuming a toxic mix of deadly drugs, including fentanyl, cocaine, ketamine, and the street drug bromazolam (a synthetic benzo), RadarOnline.comhas learned. As this outlet reported, Liuzzo’s body was discovered by hotel staff at the citizenM Miami Worldcenter on February 7, but news of his shock passing didn’t hit the headlines until April. The Miami-Dade County Medical Examiner Department has determined his death…