[worker-versioning]: unit-test for helpers deciding whether an error is retryable or not

[Shivs11]

What changed?

• Some unit-tests for the change that went in here
• Added unit-tests for the helpers, present in worker-deployment's util file, that are doing the hard work of checking if an error is retryable or not.

Why?

• Bullet proofing our feature.

How did you test it?

• built
• run locally and tested manually
• covered by existing tests
• added new unit test(s)
• added new functional test(s)

Potential risks

• None, more tests.

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Note

Strengthens coverage of retryability helpers used by worker deployment.

• Add tests for isRetryableUpdateError covering ErrWorkflowClosing, AbortedByServerErr, ResourceExhausted causes (CONCURRENT_LIMIT, BUSY_WORKFLOW), WorkflowNotReady, and MultiOperationExecution (including nil entries and mixed errors)
• Add tests for isRetryableQueryError ensuring Internal is excluded, Unavailable and history consts errors are retryable, and MultiOperationExecution behavior matches expectations
• Cleans up obsolete commented test; minor import additions for new cases

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