Move tests, rto_setup.sh and preflight.sh to docker image

[SurbhiJainUSC]

Description

• Move tests/ to docker image
• Move rto_setup.sh to src/dependencies/scripts so that it is available in docker image
• Move preflight.sh to src/dependencies/scripts so that it is available in docker image

Tests

Build docker image and verified tests/, rto_setup.sh and preflight.sh exist in the docker image

Checklist

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• 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.

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