Changes

Fix build with cmake >= 3.20 (#7445, #7447)

When running cmake to generate a project buildsystem, --build is an unknown
command line argument. Since cmake 3.20 this is rejected with an error,
and not silently ignored anymore.

Therefore, the cmake call was split into generation of the build system and
build process.

Co-authored-by: spinnau <spinnau@gmail.com>