One week after AT&T announced it would be opening its retail stores at 8 a.m. local time on July 11 for the launch of the iPhone 3G, Apple has confirmed that its own retail stores will do the same. A new message on Apple’s retail website reads “iPhone 3G Coming July 11 at 8 a.m.” In addition, the company has set up a ”Where to Buy” page for the iPhone, featuring links to find the nearest Apple retail store or AT&T…