ci: allow advisory codex review when backend is absent

Co-Authored-By: Codex <noreply@openai.com>

Author: Pigbibi

.github/workflows/codex_pr_review.yml

@@ -19,6 +19,7 @@ jobs:
     uses: QuantStrategyLab/AIAuditBridge/.github/workflows/codex_pr_review.yml@main
     with:
       caller_concurrency_key: pr-${{ github.event.pull_request.number || github.run_id }}
+      allow_unconfigured_backend: true
     secrets: inherit
     permissions:
       contents: read