test(ci): Retest security review workflow

[WesleyRosenblum]

Purpose

Controlled retest for #3280 after deploying the CodeBuild service-role permission from CR-301784045.

Expected behavior

• Author permission and pinned SHA preflight succeed.
• GitHub OIDC assumes the project-scoped launcher role.
• CodeBuild retrieves its existing GitHub source credential and proceeds beyond DOWNLOAD_SOURCE.
• The reviewer exports a verdict and reviewed SHA.
• A commit-specific status is published.

This PR is test-only and must not be merged.

[WesleyRosenblum]

Controlled retest passed end-to-end after deploying CR-301784045. CodeBuild SecurityReview-s2n-quic:ab1bc8fb-bd8d-464d-b954-89ac84303957 completed with PASS for c9d4abb, and the commit-specific security-review / report status was published successfully. Closing this test-only PR without merging.