force use of kustomize v4

With the upgrade to flux2 v0.13.4 started seeing errors about,

```
kustomize build failed: accumulating resources: 2 errors occurred:
* accumulateFile error: "accumulating resources from './monitoring/kube-prometheus-stack/crds': read /tmp/flux-system151583849/monitoring/kube-prometheus-stack/crds: is a directory"
* accumulateDirector error: "recursed accumulation of path '/tmp/flux-system151583849/monitoring/kube-prometheus-stack/crds': accumulating resources: 2 errors occurred:\n\t* accumulateFile error: "accumulating resources from 'https://raw.githubusercontent.com/prometheus-operator/prometheus-operator/v0.47.0/example/prometheus-operator-crd/monitoring.coreos.com_alertmanagerconfigs.yaml': YAML file [https://raw.githubusercontent.com/prometheus-operator/prometheus-operator/v0.47.0/example/prometheus-operator-crd/monitoring.coreos.com_alertmanagerconfigs.yaml] encounters a format error.\nerror converting YAML to JSON: yaml: line 13: mapping values are not allowed in this context\n"\n\t* accumulateDirector error: "couldn't make target for path '/tmp/kustomize-228370023/repo': unable to find one of 'kustomization.yaml', 'kustomization.yml' or 'Kustomization' in directory '/tmp/kustomize-228370023/repo'"\n\n"
```

see [this issue](fluxcd/flux2#918) for context

Signed-off-by: Jeff Billimek <jeff@billimek.com>

flux-system/kustomization.yaml

@@ -3,3 +3,7 @@ kind: Kustomization
 resources:
 - ./gotk-components.yaml
 - ./gotk-sync.yaml
+images:
+- name: ghcr.io/fluxcd/kustomize-controller
+  newName: ghcr.io/fluxcd/kustomize-controller
+  newTag: kustomize-v4-rc-de0310e7