Merge topic 'save-restore-PACKAGE_PREFIX_DIR' into release-3.29

8ac7958e3a generate_apple_*_selection_file: Save/restore PACKAGE_PREFIX_DIR
bf88879f1f generate_apple_architecture_selection_file: Avoid early returns
a4ac2c92f4 Help: Add missing section heading for apple architecture selection
b7fcc44be9 Help: Fix CMakePackageConfigHelpers typos, grammar and formatting
f1cacaa830 Tests/RunCMake/CMakePackage: Define variable closer to where it is used

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !9430