VS2022: could NOT find PkgConfig (missing: PKG_CONFIG_EXECUTABLE)

Originally reported by @CalcLoverHK when trying the Build using Visual Studio method. vcpkg reports successful install of pkgconf, however CMake still reports that option.

I remember having that error for quite some time, but unfortunately don't remember how I solved it, and can't reproduce it on my current installation. I unfortunately don't know why this happens as of today :/