Harmeet Dhillon, the Justice Department’s civil rights chief, offered a scorching critique of Major League Baseball and the San Francisco Giants for what she called a “double standard” toward religious expression — as federal officials investigate whether Christian players were pressured to wear Pride-themed hats. “It doesn’t really matter how gay San Francisco is — these workers have rights,” Dhillon told The Post in an exclusive interview Friday.   “They have a right to not be forced into a