Hello, it’s me again 
I have fixed the error @fugratwhistle. It is actually some kind of work around but seems to be functional. To disable those warnings, download from Apple’s developer download center Xcode 13.4.1. Extract the .xip file into the downloads folder.
When the extract is complete, you will probably see a prohibited symbol on Xcode’s icon. Don’t run directly Xcode from the .app directly but navigate through the package and launch the file « Xcode » located inside « Contents/MacOS/Xcode ». The older version of Xcode should be now launching.
From there, follow up the instructions to install desired packages (Should be macOS and iOS for compilation support for those target architectures). If the app suddenly exits, reopen it from the directory mentioned above until you see the home page where you can create a new project.
If you have reached this point, the main process is almost done. One step remains :
Open Terminal.app and type in the following command
sudo xcode-select --switch-version <appPath of your Xcode 13 installation>
Note : sudo mode is required to use xcode-select command while changing the selected version of the command line tools.
WARNING the path you need to enter here is the full path to the .app file where Xcode 13 is located. For example, if Xcode 13 is installed in the downloads folder, the path should be : “…/downloads/Xcode.app” only.
If the command executed successfully after you entered your administrator password, you can close the Terminal.
Now launch again your Unreal Engine project, and everything should be fine !
Note : don’t worry about new shader compilation because they need to be compiled with the new command line tools.
When those shaders has been built, package your project for macOS and all the warnings should have been gone !
I hope this will help you, because it definitely solved my issue.
Have a nice day.