refactor: add helm script and job

ci/dev/helm.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+main() {
+  cd "$(dirname "$0")/../.."
+
+  if command -v helm && helm kubeval --help > /dev/null; then
+    helm kubeval ci/helm-chart
+  fi
+
+  cd "$OLDPWD"
+}
+
+main "$@"