BUG helm chart will install but not uninstall or update

[Heiko-san]

Hi,

we created an additional datastore of type etcd using your helm chart clastix/kamaji-etcd. It successfully installs, but as soon as you try to update or delete the datastore / the helm chart, you get the following error:

helm upgrade kamaji-etcd-2 clastix/kamaji-etcd -n kamaji-etcd-2 -f values.yaml
Error: UPGRADE FAILED: post-upgrade hooks failed: admission webhook "vdatastore.kb.io" denied the request: unable to decode into *v1alpha1.DataStore: there is no content to decode

Actually it seems (most?) resources get updated. However you also get the error, if you try to kubectl delete datastores.kamaji.clastix.io kamaji-etcd-2, resulting in an half-installed datastore. It doesn't entirely get removed.

We use kamaji v0.3.3 together with cluster-api v1.5.0 with infrastructure-vsphere v1.7.0 and your kamaji plugin control-plane-kamaji v0.3.0.

[prometherion]

This is a duplicate of #38, if you don't mind I'd close this since we already have an open PR to address it: please, let me know!