By Brendan O’Brien (Reuters) -The avowed white supremacist accused of a racist attack that killed 10 people at a supermarket in a Black neighborhood in Buffalo, New York, pleaded not guilty on Thursday to 25 counts in an indictment returned by a grand jury, court documents showed. The accused shooter, Payton Gendron, appeared in court for an arraignment hearing in front of Erie County Court Judge Susan Eagan, who ordered the 18-year-old to be held without bond, local media reported. He is due back in court on July 7. Gendron was targeting Black people, authorities said, when he drove three hou…