Tests: Fix ExternalProject CONFIGURE_HANDLED_BY_BUILD on 1s filesystems
Following !5825 (merged), modify the CONFIGURE_HANDLED_BY_BUILD test to sleep 1.125 seconds to make sure the file timestamp is always updated regardless of the resolution of the underlying filesystem.
Fixes: #21830 (closed)
Backport: release
Topic-rename: test-ExternalProject-CONFIGURE_HANDLED_BY_BUILD