[CI] Delete images older than 24h. (#23291)

Signed-off-by: Qiliang Cui <derrhein@gmail.com>

.buildkite/scripts/tpu/cleanup_docker.sh

@@ -17,7 +17,7 @@ if [ "$disk_usage" -gt "$threshold" ]; then
   # Remove dangling images (those that are not tagged and not used by any container)
   docker image prune -f
   # Remove unused volumes / force the system prune for old images as well.
-  docker volume prune -f && docker system prune --force --filter "until=72h" --all
+  docker volume prune -f && docker system prune --force --filter "until=24h" --all
   echo "Docker images and volumes cleanup completed."
 else
   echo "Disk usage is below $threshold%. No cleanup needed."