As of yesterday, I'm seeing a software update notification for Command Line Tools for Xcode version 13.4. I have Xcode and the Command Line Tools for Xcode installed on my machine, but am using Xcode Version 13.3.1. I originally installed Xcode through the Mac App Store.
However, Xcode 13.4 (and its Command Line Tools) is only currently out as a Release Candidate (RC) as shown here: https://developer.apple.com/download/all/
Is it possible I've put myself into a beta/RC channel accidentally? Is there some way to prevent this from happening in the future?