Clarify Product Manager Impersonator final safe-output noop requirement

[Copilot]

The Product Manager Impersonator workflow could complete successfully without emitting any safe-output message when no viable feature idea qualified, creating a false-success path. In those cases the agent was ending in plain text instead of issuing the required noop declaration.

• Workflow prompt guardrail

  • Added an explicit final requirement in .github/workflows/gh-aw-product-manager-impersonator.md that the workflow must emit a safe-output tool call before completion.
  • If no issue qualifies, the prompt now requires the exact noop message and stops immediately rather than drifting into a narrative summary.

• Generated workflow update

  • Recompiled the generated lockfile so the shipped workflow includes the new final safe-output guardrail.

### Noop
If you cannot find a genuinely useful, non-duplicate idea that meets all the criteria above, call `noop` with:
"Product Manager Impersonator skipped — no novel, high-value feature idea found for this repository."

• Fixes [aw] Product Manager Impersonator produced no safe outputs #2010