[NDR-319] Format & limit permissions

Author: megan-bower4

.github/PULL_REQUEST_TEMPLATE.md

@@ -30,4 +30,4 @@ Tasks for all changes:
 - [ ] 5. I have considered the cross-team impact (and have PR approval from both Core & Demographics if necessary).
 - [ ] 6. I have successfully deployed this change to a sandbox and witnessed it build:
   - [ ] 6a. [`Deploy - Sandbox`](https://github.com/NHSDigital/national-document-repository-infrastructure/actions/workflows/deploy-sandbox.yml) - [workflow run: TBC](https://github.com/NHSDigital/national-document-repository-infrastructure/actions/runs/XXX)
-- [ ] 7. I have checked the Terraform Plan from this PR against `ndr-dev`.
+- [ ] 7. I have checked the Terraform Plan from this PR against `ndr-dev`.

.github/workflows/automated-pr-validator.yml

@@ -124,6 +124,8 @@ jobs:
   checklist_validator:
     name: Checklist Validation
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     steps:
     - name: Checkout repository
       uses: actions/checkout@v5