update helm linting workflow

.github/workflows/helm-lint.yml

@@ -1,10 +1,18 @@
-name: Helm Chart Linting
-description: Installs helm tooling and validates helm charts
+name: Helm Chart linting
 
 on:
-  push:
+  pull_request:
     branches:
-      - master
+    - master
+
+# This ensures that previous jobs for the PR are canceled when the PR is
+# updated.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
 
 # This ensures that previous jobs for the PR are canceled when the PR is
 # updated.