feat: add OpenClaw Docker support

[namelessman]

This pull request adds support for building and running the openclaw Docker image in the CI pipeline, along with minor consistency improvements to job naming in the workflow file. The most important changes are the addition of a new build job and Dockerfile for openclaw, as well as integration of its runtime setup and configuration.

Addition of OpenClaw support:

• Added a new job job-openclaw to .github/workflows/build-docker.yml for building and pushing the openclaw image, including its dependencies and setup script.
• Added docker_openclaw/openclaw.Dockerfile to define how the openclaw image is built, including cloning the source, installing dependencies, building the project, and copying bootstrap scripts and config templates.
• Added docker_openclaw/work/bootstrap-openclaw.sh as a startup script to initialize config, handle plugin setup, and launch the application.
• Added docker_openclaw/work/openclaw.json as a default runtime config template for the container.
• Added docker_openclaw/README.md to document build args, runtime behavior, and usage for the new image.

Workflow improvements:

• Updated job names in .github/workflows/build-docker.yml to use double quotes for consistency across all jobs. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
• Updated the sync_images job to include job-openclaw in the list of dependencies, ensuring the new image is pushed to the mirror registry.

[CLAassistant]

All committers have signed the CLA.