test: Fix NodeCleanMetadata by using --overwrite
test: Fix NodeCleanMetadata by using --overwrite

Fixes the following errors:
```
cmd: "kubectl annotate nodes k8s1 io.cilium.network.ipv4-pod-cidr" exitCode: 1 duration: 76.869764ms stdout:

stderr:
error: at least one annotation update is required
```

Signed-off-by: Thomas Graf <5f50a84c1fa3bcff146405017f36aec1a10a9e38@cilium.io>

cilium/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium,michi-covalent/cilium,cilium-team/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,tklauser/cilium,michi-covalent/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,cilium-team/cilium