Does Anna Wintour have a new DSA pet? In a Vogue cover story released Tuesday to promote the upcoming “The Devil Wears Prada” sequel, Wintour and Meryl Streep — who plays Miranda Priestly, the fictionalized version of the powerful former editor — team up for a Q&A conducted by director Greta Gerwig. The 76-year-old stepped down from the magazine last June but still remains atop Condé Nast as its chief content officer. And never has the icy Wintour looked so playful. There she is with Streep in