A system cmake is not auto-detected, QtCreator expects an "own" cmake from the optional package in "Developer and Designer Tools"

Steps to reproduce:

• It might happen that you do not select the optional "Developer and Designer Tools". Through this, you would not get the Cmake and Ninja preinstalled with the Qt Installer, but you might have cmake still installed. Or event more: you deliberately decide to not install Cmake from "Developer and Designer Tools" since you know what you already installed it aside of the Qt installation
• After this, you still have an option to select and use cmake in a Qt Creator project
• Create a Qt Console Application with the New Project wizard with QtC 4.15.1 on a Apple Silicon Mac on MacOS 11.4 . Select cmake as build toolchain. After the wizard has been finished, the project shows up with disabled kits, since cmake failed to be configured
• System cmake is not detected even though it is in the PATH

A manual addition of cmake fixes the problem. It does not seem to be OK, that Qt Creator cannot detected and use a system cmake available in the PATH.