Improve CI scan duplicate detection

[svick]

Why

The ML.NET CI scanner instructions were modeled on dotnet/runtime and copied its claim that Arcade publishes a Build_Analysis_KnownIssues_v1 AzDO attachment. Investigation found no producer or retained machinelearning build containing that attachment; all 20 available definition 167 builds returned an empty attachment collection.

Build Analysis results are available instead through the Build Analysis GitHub check on the build's source commit. The scanner should use positive issue links from that check as dedup evidence, while treating misses as inconclusive because large rendered reports can be truncated.

The copied search guidance also lacked a rule to preserve complete underscore-delimited test identifiers. In a real ML.NET example, searching AutoMLExperiment_return_current_best_trial_when_ct_is_canceled_with_trial_completed_Async finds KBE #7418, while the shortened stem returns no results.

Changes

• Replace the nonexistent AzDO attachment with an actionable GitHub Checks API query.
• Wire that query into the dedup step as a positive-only signal.
• Require complete test method identifiers to be searched verbatim before deriving shorter stems.

Validation

• Queried build 1520792's source commit and found completed Build Analysis check 88824261755.
• Verified the complete test identifier finds AutoMLExperiment_return_current_best_trial_when_ct_is_canceled_with_trial_completed_Async fails in CI #7418 and the shortened identifier returns no results.
• Confirmed no Build_Analysis_KnownIssues_v1 references remain under .github.

Corresponding runtime change: dotnet/runtime#131312

cc: @kotlarmilos

Note

This pull request description was generated with GitHub Copilot.

[Copilot]

Pull request overview

Updates the ML.NET CI scan playbook/instructions to improve known-issue deduplication by switching from a nonexistent AzDO Build Analysis attachment to the actionable GitHub “Build Analysis” check output, and by tightening issue-search guidance for underscore-delimited test identifiers.

Changes:

• Replaces the prior AzDO Build_Analysis_KnownIssues_v1 attachment guidance with a GitHub Checks API (gh api .../commits/{sha}/check-runs) approach.
• Clarifies dedup behavior: treat Build Analysis matches as a positive-only suppression signal; treat misses as inconclusive and continue searching.
• Requires searching complete underscore-delimited test method identifiers verbatim before deriving shorter stems.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
.github/skills/ci-scan/references/playbook.md	Updates the Step 5 dedup procedure to incorporate the Build Analysis GitHub check as a positive-only signal and to continue exact searches after misses.
.github/skills/ci-scan/references/ci-scan.instructions.md	Replaces outdated Build Analysis attachment guidance with a GitHub check-runs query, and adds explicit guidance to search full underscore-delimited test identifiers verbatim.