Hillary Clinton is scheduled to speak to a gathering of top New York state Democrats next week — amid speculation that she could seek the White House again as President Joe Biden’s poll numbers continue to plunge. Clinton, who was heavily favored to win the 2016 presidential election before being upset by Donald Trump, is set to address the state Democratic Committee’s Nominating Convention on Feb. 17, a source familiar with the matter told The Post on Thursday. It’s unclear who, if anyone, Clinton will endorse during the event at the Sheraton New York Times Square hotel, which will kick...