RMN tests CI reliability and one new test scenario

[dimkouv]

Pull Request Description: Improve RMN Test Reliability and Add New Test Case

Summary

This PR makes the following changes to improve test reliability and enhance test coverage for RMN:

1. Re-enabled RMN Tests:

   • Shifted tests to use CLL-managed runners instead of GitHub shared runners.
   • This transition helps prevent flakiness and ensures a more stable testing environment.

2. Added a New Test Case:

   • Introduced a test scenario where a chain is cursed and then uncursed, verifying expected behavior in both states.

Why These Changes?

• The flakiness of tests on shared runners was causing unnecessary delays and reducing confidence in CI reliability.
• Adding the cursed-to-uncursed test case strengthens coverage for edge-case scenarios, ensuring robust functionality.

Testing and Validation

• Verified that RMN tests run reliably on the CLL-managed runners (performed 5 retries).
• Ensured that the new test case passed under expected conditions and did not introduce regressions.

Impact

• Improved reliability and predictability of CI pipelines.
• Enhanced confidence in the correctness of RMN functionality.