Use the docker compose plugin instead of a standalone binary

- install docker-compose-plugin from the docker repo and remove /usr/local/bin/docker-compose (pinned 2.29.0)
- remove the legacy download_docker_com_linux_debian.list (no signed-by), which made apt refuse the docker sources

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

defaults/main.yml

@@ -4,4 +4,3 @@ cloud_storage: /opt/storage
 cloud_stage: prod
 cloud_update: false
 
-docker_compose_version: 2.29.0