By Dan Gartland She says she wants to grow her family. Good morning, I’m Dan Gartland. It’s rare for a summer morning to start out with sports news this monumental. In today’s SI:AM: 🎾 Serena’s impending retirement 🏈 Breaking down the college football schedule 🏀 Kevin Durant’s ultimatum If you’re reading this on SI.com, you can sign up to get this free newsletter in your inbox each weekday at SI.com/newsletters. Goodbye to the GOATSerena Williams, the greatest women’s tennis player in history—perhaps the greatest tennis player in history, period—is retiring from the game, but not right this mo…