It was supposed to be a celebration of a playoff team, a love affair between the town and the team, ringing in the new year with a Super Bowl resolution. It is forecast to be 21 degrees come 4 p.m. on New Year’s Eve, the merciful end of a season that cannot end soon enough for all New York Football Giants. Especially Eli Manning. If there is any reason for you to watch what is left of your Giants, who will have every chance to lose their franchise-record 14th game against the Redskins with as many interims as wins, it should be to sing Auld Lang Syne to Eli Manning and say goodbye. No one knows, of course. Nothing is etched in stone. But the icy winds of change are blowing, and it is impossible not to feel them. No one knows what the next Giants GM and next Giants head coach will think of Josh Rosen and Sam Darnold. No one knows what they will think of Davis Webb, partly because the Giants somehow are finding a way not to play him in a season when what could go wrong has gone wrong, becoming Mara’s Law. John Mara declaring that he wants Manning back is what you would expect a co-owner to say about a quarterback who has delivered two Super Bowl championships to New York.