Instagram reinstated presidential hopeful Robert F. Kennedy Jr.’s account on Sunday after a two-year ban that was triggered by the anti-vaxxer’s claims about the COVID-19 vaccine. Kennedy’s account was yanked from the app in 2021 over “repeatedly sharing debunked claims about the coronavirus or vaccines,” a spokesperson told The Post at the time. The prominent anti-vaccine activist and environmental lawyer touted 800,000 followers on the platform when his account was banned. Since getting his account back on Sunday — two months after the Democrat announced his White House bid — Kennedy boasts 773,000 followers and a blue “verified” check mark...