Lucy Nicholson/ReutersIt didn’t seem like things could get much worse for MedMen, the onetime cannabis industry “unicorn” that rode a $3 billion valuation in 2018 all the way down to a present-day stock price of $0.But the beleaguered company—which has seemingly collapsed in slow-motion—now owes nearly $2 million in back rent to billionaire New York real estate mogul Jack Cayre, who finally ran out of patience on Thursday, according to a default notice obtained by The Daily Beast.“Please be advi