The summer of Barbie has its own soundtrack! “Barbie: The Album” was released in full on July 21, alongside the highly anticipated “Barbie” movie, and the soundtrack is a gift that just keeps on giving. On Aug. 16, Charli XCX released a “Barbie”-themed music video for her song “Speed Drive,” and in the middle of the video, she stops everything to take a video call from Sam Smith, who also appears on the “Barbie” soundtrack. Smith seems to ask her about an upcoming joint project, hinting at a…