Use Compose v2 for docker-compose compatibility

[Haihan-Jiang]

Summary

• stop installing the legacy docker-compose v1 apt package in the Docker builder image
• keep the docker-compose command name available through a small wrapper around docker compose
• add build-time checks that docker-compose --version works and the wrapper reports the same Compose v2 version as docker compose version

Fixes #1042.

Validation

• git diff --check
• docker build --file=Dockerfile-base --tag=us-docker.pkg.dev/cloud-builders-dev/cloud-builders/docker-base .
• docker build --file=Dockerfile-versioned --build-arg=DOCKER_VERSION=5:24.0.9-1~ubuntu.20.04~focal --tag=cloud-builders-docker-compose-v2-test .
• docker run --rm --entrypoint /bin/sh cloud-builders-docker-compose-v2-test -c 'docker compose version && docker-compose --version && test "$(docker compose version --short)" = "$(docker-compose version --short)"'
• confirmed the image contains docker-compose-plugin 2.35.1-1~ubuntu.20.04~focal
• confirmed the image does not contain the legacy docker-compose package