* fix: correct YAML indentation error in docker workflow
- Fix incorrect indentation at line 237 in .github/workflows/docker.yml
- Step 'Extract metadata and generate tags' had 12 spaces instead of 6
- This was causing YAML syntax validation to fail
* fix: restore unified build-rustfs task with correct YAML syntax
- Revert complex job separation back to single build-rustfs task
- Maintain Linux and macOS builds in unified matrix
- Fix YAML indentation and syntax issues
- Docker builds will use only Linux binaries as designed in Dockerfile
* feat: implement precise Docker build triggering using workflow_run
- Use workflow_run event to trigger Docker builds independently
- Add precise Linux build status checking via GitHub API
- Only trigger Docker builds when both Linux architectures succeed
- Remove coupling between build.yml and docker.yml workflows
- Improve TARGETPLATFORM consistency in Dockerfile
This resolves the issue where Docker builds would trigger even if
Linux ARM64 builds failed, causing missing binary artifacts during
multi-architecture Docker image creation.
