Update GitHub Actions workflow for Docker build

[Harsche]

This pull request adds a new GitHub Actions workflow to automate building Docker images for the project. The workflow is triggered on pushes and pull requests to the main branch, and includes steps for checking out the repository, setting up Docker Buildx, building the Docker image, and listing built images. Steps for logging into Docker Hub and pushing images are included but currently commented out.

Continuous Integration workflow setup:

• Added .github/workflows/blank.yml to define a CI workflow that builds Docker images on push or pull request events to the main branch.
• Configured steps for repository checkout, Docker Buildx setup, Docker image building, and listing images.
• Included (but commented out) steps for Docker Hub login and image push, allowing easy future enablement for publishing images.

[Copilot]

Pull Request Overview

This PR adds a GitHub Actions CI workflow to automate Docker image building for the project. The workflow triggers on pushes and pull requests to the main branch and includes essential Docker build steps with optional image publishing capabilities.

• Adds automated Docker image building on CI events
• Includes repository checkout, Docker Buildx setup, and image building steps
• Provides commented-out Docker Hub login and push functionality for future use

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