By Jonathan Allen and Brendan O’Brien NEW YORK (Reuters) – More than 7,000 nurses in New York City ended a three-day strike and returned to work on Thursday after reaching tentative deals with hospitals over staffing levels and pay increases, the New York State Nurses Association (NYSNA) said. Nurses at Montefiore Medical Center in the Bronx and Mount Sinai Hospital in Manhattan had taken to picket lines saying they were more concerned with patient safety than higher wages. As news of the deal spread, including a guarantee of better ratios of staff to patients, nurses in scrubs cheered and emb…