By City A.M. Reporter A knife attacker killed six people and injured several others in a stabbing spree at a Sydney shopping centre before being shot dead by police. The lone knifeman attacked shoppers on Saturday afternoon at the Westfield shopping centre in the suburb of Bondi Junction in eastern Sydney. A female New South Wales Police inspector has been hailed as a hero after she confronted the attacker on her own and shot him dead as he raised a knife and lunged at her. Police said they had identified the attacker as a 40-year-old man who was known to them, but added that they do not think…