TURIN, Italy—Novak Djokovic claimed a record-equaling sixth ATP Finals title by beating the third-seeded Casper Ruud on Sunday to top a fantastic finish to the season for the Serb. Djokovic won 7–5, 6–3 to secure his first title at the event since 2015 and match Roger Federer’s record. The 35-year-old Djokovic, who had lost his…