NEW YORK — A jury awarded more than $1.2 million to Robert De Niro’s former personal assistant Thursday, finding one of his companies responsible for subjecting her to a toxic work environment.While the jury found De Niro was not personally liable for the abuse, it said his company, Canal Productions, engaged in gender discrimination and retaliation against former assistant Graham Chase Robinson and should make two payments of $632,142 to her.De Niro, who spent three days at the two-week trial — including …