I had the same issue. To fix I had to download and change Xcode to 15.0 beta 2 and command line tools to 15.0 beta 2.
You can actually just download Xcode without deleting a newer one, just make sure you go to Xcode -> Settings -> Locations -> Command Line Tools and set it to "Xcode-beta 15.0". Then reload the Terminal and make sure you have the command line tools version 15.0 running pkgutil --pkg-info=com.apple.pkg.CLTools_Executables