Optimize CLT test balancing across runners

Proposal:

Currently, CLT tests run in parallel (I believe across 8 runners), but the workload is poorly balanced. For example, one runner may take 15 minutes to finish while another completes in just 2 minutes, which makes the overall execution inefficient.

A possible solution is to store the execution time of each test in the GitHub Actions cache and use this historical data to distribute tests more evenly across runners on subsequent runs

Checklist:

To be completed by the assignee. Check off tasks that have been completed or are not applicable.

• Implementation completed
• Tests developed
• Documentation updated
• Documentation reviewed
• OpenAPI YAML updated and issue created to rebuild clients