set contents read permission

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

Author: nicktrn

.github/workflows/release-helm.yml

@@ -18,6 +18,8 @@ env:
 jobs:
   lint-and-test:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     steps:
       - name: Checkout
         uses: actions/checkout@v4