Now for the bad. Something has changed in a images of MacOs environments. Looking for users of this operating system. Yo need in file https://github.com/urho3d/Urho3D/blob/master/.github/workflows/main.yml replace
run: sudo xcode-select -s '/Applications/Xcode_12.app' to something from this https://github.com/actions/virtual-environments/tree/main/images/macos and force the engine to compile. Otherwise, we will not be able to guarantee support for MacOS.