British singer Sam Fender is set to headline next year's Glastonbury Festival, where he will take to the main Pyramid Stage in June 2027, according to reports from The Mail on Sunday. Although the festival's official line-up will not be confirmed until spring, sources close to the festival have confirmed that the 32-year-old singer will be one of the headliners at the upcoming festival. Fender is enjoying a successful period in his career, parti…