feat: build vllm-rocm

[jpekmez]

This PR introduces a new workflow for building and pushing Docker images to Google Cloud Platform (GCP). It sets up Docker Buildx, authenticates with GCP, and configures Docker to use the GCP Docker registry.

Changes:

• Dockerfile.rocm: The BASE_IMAGE argument is updated to use a different version of the ROCM PyTorch image.
• Makefile: A new build target is added to build the Docker image using the updated Dockerfile.rocm. The push target is also added to push the built image to the GCP Docker registry.
• build-and-push.yaml: A new workflow file is introduced to automate the build and push process. It sets up Docker Buildx, authenticates with GCP, and configures Docker to use the GCP Docker registry.

[github-actions]

👋 Hi! Thank you for contributing to the vLLM project.
Just a reminder: PRs would not trigger full CI run by default. Instead, it would only run fastcheck CI which starts running only a small and essential subset of CI tests to quickly catch errors. You can run other CI tests on top of those by going to your fastcheck build on Buildkite UI (linked in the PR checks section) and unblock them. If you do not have permission to unblock, ping simon-mo or khluu to add you in our Buildkite org.

Once the PR is approved and ready to go, your PR reviewer(s) can run CI to test the changes comprehensively before merging.

To run CI, PR reviewers can do one of these:

• Add ready label to the PR
• Enable auto-merge.

🚀