chore: Add helper scripts for tests shards-splitting

[danskmt]

Pull Request Submission Checklist

• Follows CONTRIBUTING guidelines
• Commit messages
  are release-note ready, emphasizing
  what was changed, not how.
• Includes detailed description of changes
• Contains risk assessment (Low | Medium | High)
• Highlights breaking API changes (if applicable)
• Links to automated tests covering new functionality
• Includes manual testing instructions (if necessary)
• Updates relevant GitBook documentation (PR link: ___)
• Includes product update to be announced in the next stable release notes

What does this PR do?

Where should the reviewer start?

How should this be manually tested?

What's the product update that needs to be communicated to CLI users?

[snyk-io]

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