Isabel Oakeshott is joining GB News to host a new weekly political programme on Fridays, the channel announced today. The Friday edition of The Briefing: PM is the fourth new show arriving as part of the upcoming relaunch, alongside others from Tom Harwood, Gloria De Piero, and Darren McCaffrey. The relaunch is set for later this month. A packed lineup now, though there’s still one notable absence at the top…