Fix cassandra nodetool test failure

[HadhemiDD]

What does this PR do?

Add a default cassandra docker version to fix the test failing.

Root cause of the issue #22131 CASSANDRA_VERSION is empty during the Docker build, so the FROM becomes FROM cassandra: (invalid) => This is a Docker BuildKit issue (it seems to be updated on Feb 9th)

Motivation

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Add the qa/skip-qa label if the PR doesn't need to be tested during QA.
• If you need to backport this PR to another branch, you can add the backport/<branch-name> label to the PR and it will automatically open a backport PR once this one is merged

[github-actions]

⚠️ Recommendation: Add qa/skip-qa label

This PR does not modify any files shipped with the agent.

To help streamline the release process, please consider adding the qa/skip-qa label if these changes do not require QA testing.

[datadog-official]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.03%. Comparing base (de966db) to head (7a5dec7).
⚠️ Report is 4 commits behind head on master.

Additional details and impacted files

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