Make pipeline artifacts retry-safe

[Sean McManus (sean-mcmanus)]

Summary

Give pipeline artifacts names based on their producing job attempt so job retries do not collide with artifacts already published in the same run. Update the matching downloaders to select the current producer's output rather than using the consuming job's attempt number.

This PR was investigated and created by GitHub Copilot (in VS Code). Any message starting with ✨Copilot: was sent by Copilot.

Details

• Qualify VSIX and LLDB-MI artifact names with the producing job's attempt.
• Resolve artifact and timeline metadata before downloading, reject stale outputs from earlier attempts, and support historical fixed-name inputs.
• Preserve package filenames, download destinations, signing inputs, and the existing typed release artifact validation.
• Retain the localization drop name pending confirmation of its external reader contract.

Validation

• Resolver tests passed on PowerShell 7 and Windows PowerShell 5.1; coverage includes retries, historical inputs, malformed metadata, and exact build selection.
• YAML contract checks pass for producer naming, reader wiring, and documented exceptions.
• The tests execute the actual inline resolver using offline metadata; they do not execute Azure's artifact publication service. Runtime pipeline/retry validation remains necessary.