CHICAGO — Chicago Cubs players and coaches gathered along the foul line near third base, clapping in unison while “Go Cubs Go” blared across Wrigley Field for the final time this year. The celebration after an 8-1 win Sunday against the Cincinnati Reds continued the team’s postgame tradition throughout the season, a sing-along to the song synonymous with home victories. Willson Contreras lingered afterward, taking in the scene as he slowly made his way behind home plate, where he was greeted by family. Sunday’s game likely was Contreras’ final home game at Wrigley. Although he proclaimed at th…