To fix this issue, add a permissions block to the workflow file .github/workflows/postsubmit.yaml. The block should be placed at the root, above the jobs: key, making the permission settings apply to all jobs unless overridden by the reusable workflow or within specific jobs. As the optimal least-privilege configuration depends on what the invoked workflow and jobs do, a safe starting point is contents: read, which is the most restrictive and recommended by GitHub for workflows that do not require write access; you can add other entries (like pull-requests: write) only if required. Since the shown code doesn't indicate any write operations, using only contents: read is appropriate.

Edit the file .github/workflows/postsubmit.yaml to add:

permissions:
  contents: read

This should be inserted after the name: and before the on: line.

No other methods, imports, or changes are required for this fix.