The Dagger container running generate_build_history.py may not always
reach the deployment server (network constraints on the Dagger engine).
Rather than aborting the entire publish-website pipeline, log the SSH
verbose output (already added in the previous debug commit) and return
an empty file list so Hugo still builds and rsync still deploys the
site — just without updated build-history pages.
This unblocks the cron deploy that has been failing since c259d2da.