Yesterday, workers removed the iconic neon sign outside Carnegie Deli, but the final nail in the coffin comes from the news that mega-developer Extell is buying the pastrami mecca’s former home on a block where they already own two other sites. The Post got word that Gary Barnett’s firm will close on a deal as soon as today for the six-story building at 854 Seventh Avenue. The 79-year-old deli closed on December 31st, but in 2015, Extell paid $9.1 million to owner Marian Harper Levine for their air rights.