SACRAMENTO, Calif. — Sirhan Sirhan, who assassinated presidential candidate Robert F. Kennedy in 1968, is asking a judge on Wednesday to free him from prison by reversing California Gov. Gavin Newsom’s denial of his parole earlier this year.Sirhan shot Kennedy moments after the U.S. senator from New York claimed victory in California’s pivotal Democratic presidential primary. He wounded five others during the shooting at the Ambassador Hotel in Los Angeles.Newsom said in January that Sirhan remains a …