the prune learns restraint, build cache survives the deploy

@@ -103,7 +103,8 @@ MIGRATE    fi    cat >> "/srv/git/${name}.git/hooks/post-receive" << TAIL    docker system prune --force    docker container prune --force    docker image prune --force    END_TIME=\$(date +%s)    echo "Total build time: \$((END_TIME - START_TIME))s"  fi