The type of military-style rifle used in former President Donald Trump’s assassination attempt over the weekend — and numerous other mass shootings — is being given away as a raffle prize at the Republican National Convention. Trump on Saturday was left with a bloodied ear after being grazed by a bullet fired from an AR-15 by shooter Thomas Crooks, authorities have said. Days after the shooting in Butler, Pennsylvania, rally, which left two dead including the shooter, MAGA supporters in Milwaukee can enter a free giveaway at the convention to win their very own AR-15, Rolling Stone reported. W…