CSI Api version is deprecated

[Gordonby]

The secrets-store.csi.x-k8s.io/v1alpha1 API is deprecated. The sample should shift to use secrets-store.csi.x-k8s.io/v1 instead.

I'd supply a PR for this, however I'm also not clear why the script is using cat <<EOF to perform string manipulation of the manifest fille when helm is already being used in the repository for the app. Helm has the primary benefit of cleaning up this dynamic parameter string insertion technique into something much neater.