By Steve Holland MANCHESTER, New Hampshire (Reuters) -As New Hampshire voters prepared to cast their votes in the state’s first-in-the nation primary Tuesday, a robocall is circulating in the state urging Democrats to stay home – using a fake audio of U.S. President Joe Biden. “It’s important that you save your vote for the November election….voting this Tuesday only enables the Republicans in their quest to elect Donald Trump again,” the call says. The White House confirmed Monday that the call was not recorded by Biden and said the incident highlights the challenges emerging technologies pre…