apps: remove unnecessary kustomizations

apps/do/do-test/kustomization.yaml

-apiVersion: kustomize.config.k8s.io/v1beta1
-kind: Kustomization
-resources:
-  - vikunja-oauth-client.yaml
-  - vikunja-release.yaml
-  - vikunja-values-configmap.yaml
-  - vikunja-postgres-pvc.yaml

apps/do/vikunja/kustomization.yaml

-apiVersion: kustomize.config.k8s.io/v1beta1
-kind: Kustomization
-resources:
-  - vikunja-oauth-client.yaml
-  - vikunja-release.yaml
-  - vikunja-values-configmap.yaml
-  - vikunja-postgres-pvc.yaml
-  - vikunja-files-pvc.yaml

apps/ninja/invoiceninja/kustomization.yaml

-apiVersion: kustomize.config.k8s.io/v1beta1
-kind: Kustomization
-resources:
-  - invoiceninja-mariadb-pvc.yaml
-  - invoiceninja-pvc.yaml
-  - invoiceninja-release.yaml
-  - invoiceninja-values-configmap.yaml

apps/people/suitecrm/kustomization.yaml

-apiVersion: kustomize.config.k8s.io/v1beta1
-kind: Kustomization
-resources:
-  - suitecrm-values-configmap.yaml
-  - suitecrm-release.yaml