Deutsche Bank AG is cutting itself free of The Cosmopolitan Casino of Las Vegas, a resort and casino, saying it’s selling the swanky but unprofitable high-rise complex on the Strip to Blackstone Real Estate Partners VII for $1.73 billion. The German investment bank said in a statement Thursday that the cash deal remains subject to regulatory approvals. The bank had intended to sell the property from before it even opened in 2010 and had placed The Cosmopolitan in a separate bank division devoted to winding down or selling unwanted investments. The last major Las Vegas resort approved before the Great…