NEW YORK — As a high-stakes competition unfolds for one of New York’s coveted casino licenses, an unusual struggle is emerging between Nassau County officials and Hofstra University. The private college in Hempstead has come out firmly against a plan backed by Las Vegas Sands to build a casino at the site of the nearby Nassau Coliseum. A lawsuit by Hofstra stopped a lease transfer that left the bid in limbo. But the dispute took a dramatic and unexpected turn this week when Nassau County accused Hofstra of “colluding” with a rival bid for a casino in Queens backed by New York Mets owner Steve …