fix(gooddata-eval): propagate best_run_latency_s on guardrail's no-verdict path

CodeRabbit catch on #1845: the JudgeResponseError raised when no run's judge
verdict was readable at all left best_run_latency_s unset, unlike the
equivalent branch in general_question.py.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: Tomkess

packages/gooddata-eval/src/gooddata_eval/core/agentic/guardrail.py

@@ -290,10 +290,12 @@ def _write_scores(ctx: RunTraceContext) -> None:
     if not summary.scored_run_results:
         # No readable verdict for any run: an error, not K failures. Raised after the
         # trace link is queued so whatever the agent did is still linked.
-        raise JudgeResponseError(
+        exc = JudgeResponseError(
             f"judge returned no readable verdict for any of the {len(summary.run_results)} run(s): "
             + " | ".join(unscored)
         )
+        exc.best_run_latency_s = summary.best.run_latency_s
+        raise exc
 
     runs_passed = sum(1 for r in summary.scored_run_results if r.passed)
     runs_effective = len(summary.run_results)