Merge topic 'ExternalProject-stamp-cfgdir' into release-3.24

6a1e45fdec Merge branch 'backport-3.23-ExternalProject-stamp-cfgdir'
5022b42f8b ExternalProject: Fix regression in stamp creation for Xcode+iOS
7b622f3e80 ExternalProject: Fix regression in stamp creation for Xcode+iOS

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Craig Scott <craig.scott@crascit.com>
Merge-request: !7396