Sir Paul McCartney has marked what would have been John Lennon’s 84th birthday with a touching tribute on social media. The 82-year-old Beatles legend took to Instagram on Wednesday to share a poignant image from a 2022 performance. The photograph shows McCartney on stage with projected footage of Lennon playing guitar behind him. “Happy Birthday John. Thanks for being there,” McCartney captioned the post. The tribute comes in the wake of McCartney’s recent revelations about mending his friendship with Lennon before the latter’s tragic death in 1980. The image, taken from Peter Jackson’s Disne…