MATTHEW CHILDS BRITAIN’S Prince Philip, the 99-year-old husband of Queen Elizabeth, left a London hospital yesterday after a four-week stay for treatment for an infection and to have a heart procedure. Philip, the Duke of Edinburgh, was admitted to the private King Edward VII's Hospital on February 16 after he felt unwell and was given treatment for an unspecified, but not COVID-19-related, illness. He was transferred briefly at the start of this month to a specialist cardiac centre at another London hospital, where he underwent a successful procedure for a pre-existing heart condition. A Reuters witness said the duke left…