Linux startup script added directly.

gcloud compute instances create instance-1 --project=gkecluster-423317 --image=debian-12-bookworm-v20250513 --image-project=debian-cloud --machine-type=n1-standard-1 --zone=us-central1-f --preemptible --no-restart-on-failure --maintenance-policy=terminate --boot-disk-size=10GB