[OPERATOR] PodDisruptionBudget is deployed even if ETCD has 1 replicas

- [ ] I have searched the [issues](https://github.com/apache/openserverless/issues) of this repository and believe that this is not a duplicate.

### Ⅰ. Issue Description

If we deploy Openserverless with `etcd.config.replicas: 1`, the Operator still deploys the PodDisruptionBudget (nuvolaris-etcd) resource and this prevents node drains.

### Ⅱ. Describe what happened

PodDisruptionBudget (nuvolaris-etcd) resource prevents k8s node drains (and a manual change on PDB resource is required to make the drain go ahead)

### Ⅲ. Describe what you expected to happen

PodDisruptionBudget (nuvolaris-etcd) should not be deployed if Openserverless is configured with `etcd.config.replicas: 1`.

### Ⅳ. How to reproduce it (as minimally and precisely as possible)

1. Deploy Openserverless with `etcd.config.replicas: 1`
2. Drain a master node

Minimal yet complete reproducer code (or URL to code):

### Ⅴ. Anything else we need to know?

The issue is probabily related to this file:
[https://github.com/apache/openserverless-operator/blob/main/deploy/etcd/etcd-policy.yaml](https://github.com/apache/openserverless-operator/blob/main/deploy/etcd/etcd-policy.yaml)

Maybe a condition should manage the deployment (or not) of manifest above.

### Ⅵ. Environment:

- K8S Runtime and version: k3s v1.29.3+k3s1
- OPS CLI version: 0.1.0-2409121919.dev

Inizia da deploy/etcd/etcd-policy.yaml e analizza come l’Operator esegue il rendering di questo manifest a partire da etcd.config.replicas. Riproduci il deployment con una replica e conferma che il PodDisruptionBudget blocca lo svuotamento del nodo. Il lavoro è completato quando il PDB è assente per una replica, mentre il comportamento esistente rimane invariato per un numero maggiore di repliche.

Scritto dal modello di indicizzazione a partire dal testo della issue.