Potential fix for code scanning alert no. 9: Workflow does not contain permissions

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: justlevine

.github/workflows/test.yml

@@ -196,6 +196,8 @@ jobs:
   # - Uploads HTML coverage report as an artifact (if coverage is enabled).
   phpunit:
     name: Test PHP ${{ matrix.php }} WP ${{ matrix.wp }}${{ matrix.coverage && ' with coverage' || '' }}
+    permissions:
+      contents: read
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false