ci: reflect trigger reason in pipeline run name and warn on ADO YAML changes

[saurabhrb]

Summary

Two CI-side improvements to the eval pipeline plumbing — no skill or plugin changes.

Pipeline run name (.azdo/DataversePluginEvals_PR.yml)

PR run buildId=20097004 still rendered as ... • plugin-main • ... because the YAML used a label parameter (default: 'plugin-main') in the run name format. Parameter defaults are baked at queue time and auto-triggered (pr / ci) runs can't override them — only "Run pipeline" manual queues can — so every auto run leaks the default label.

Fix: drop the label parameter and use Azure Pipelines runtime variables instead:

name: $(Date:yyyyMMdd)$(Rev:.r) • ${{ parameters.mode }} • $(Build.Reason)$(System.PullRequest.PullRequestNumber) • ${{ parameters.testFile }}

Resulting run names:

• PR build → 20260516.1 • dry-run • PullRequest61 • dv_data.biceval.json
• CI on main → 20260516.1 • dry-run • IndividualCI • dv_data.biceval.json
• Manual queue → 20260516.1 • dry-run • Manual • dv_data.biceval.json

The mode and testFile parameters stay — those are user-facing knobs for manual runs.

ADO YAML change warning workflow (.github/workflows/ado-pipeline-yaml-pr-warning.yml)

Modeled on the equivalent workflow in microsoft/PowerPlatform-DataverseClient-Python. Triggers on PRs that touch .azdo/DataversePluginEvals_PR.yml and:

1. Emits a ::warning:: line in the workflow log
2. Adds a Step Summary
3. Posts a resolvable PR review comment pointing at the file, reminding the reviewer to re-enable / approve the updated YAML in ADO (definition 32010) post-merge

Closes the manual recall step that bit us when the pipeline default branch was migrated to main.

Not in scope

• No skill files touched → no version bump required
• Static eval (python .github/evals/static_checks.py) passes