update helm linting workflow

.github/workflows/helm-lint.yml

@@ -1,8 +1,7 @@
-name: Helm Chart Linting
-description: Installs helm tooling and validates helm charts
+name: Helm Chart linting
 
 on:
-  push:
+  pull_request:
     branches:
     - master
 
@@ -15,6 +14,15 @@ concurrency:
 permissions:
   contents: read
 
+# 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
+
 jobs:
   release:
     runs-on: ubuntu-latest