[CICD enhance] DocIndexRetriever run CI with latest base image, group logs in GHA outputs.

[chensuyue]

Description

1. Enable latest base image test for CI.
2. Group log lines in GHA outputs for better readable logs.

Issues

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Type of change

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds new functionality)
• Breaking change (fix or feature that would break existing design and interface)
• Others (enhancement, documentation, validation, etc.)

Dependencies

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Tests

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[github-actions]

Dependency Review

✅ No vulnerabilities or license issues found.

Scanned Files

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[Copilot]

Pull Request Overview

This PR enhances the CI process for DocIndexRetriever by enabling tests with the latest base image and improving log grouping in GitHub Actions outputs.

• Updated build arguments to use environment variables for IMAGE_REPO and BASE_TAG, enabling more flexible image builds.
• Adjusted the Docker image build configuration to support the CI enhancement.

Files not reviewed (6)

• DocIndexRetriever/Dockerfile: Language not supported
• DocIndexRetriever/tests/test_compose_milvus_on_gaudi.sh: Language not supported
• DocIndexRetriever/tests/test_compose_milvus_on_xeon.sh: Language not supported
• DocIndexRetriever/tests/test_compose_on_gaudi.sh: Language not supported
• DocIndexRetriever/tests/test_compose_on_xeon.sh: Language not supported
• DocIndexRetriever/tests/test_compose_without_rerank_on_xeon.sh: Language not supported