Move integration tests to tests/integration and unit tests to tests/unit

[SurbhiJainUSC]

Description

• Move all integration tests to tests/integration
• Move all unit tests to tests/unit
• Move all smoke tests to tests/integration/smoke

Tests

CI tests

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code. For an optional AI review, add the gemini-review label.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed, including adding new documentation pages to the relevant Table of Contents (toctree directive) as explained in our documentation.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[github-actions]

🤖 Hi @SurbhiJainUSC, I've received your request, and I'm working on it now! You can track my progress in the logs for more details.

[github-actions]

📋 Review Summary

This pull request refactors the test directory structure by organizing tests into unit, integration, and integration/smoke directories. The changes are well-executed and improve the project's maintainability. The related paths in configuration, documentation, and scripts have been updated accordingly.

🔍 General Feedback

• The restructuring is a positive step towards a more organized and scalable test suite.
• The use of pytest.mark.integration_test is a good practice for separating test types.
• One minor suggestion was made to use os.path.join for path construction to improve cross-platform compatibility.

Overall, this is a solid contribution that improves the project's structure.

[hengtaoguo]

Thanks for the refactor!