[Bug]: kubectl-cnpg 1.29.1 cannot generate 1.28.2/1.28.3 manifests although 1.28.1 works

### Is there an existing issue already for this bug?

- [x] I have searched for an existing issue, and could not find anything. I believe this is a new bug.

### I have read the troubleshooting guide

- [x] I have read the troubleshooting guide and I think this is a new bug.

### I am running a supported version of CloudNativePG

- [x] I have read the troubleshooting guide and I think this is a new bug.

### Contact Details

info@marcschaeferger.de

### Version

1.29 (latest patch)

### What version of Kubernetes are you using?

1.34

### What is your Kubernetes environment?

Other

### How did you install the operator?

YAML manifest

### What happened?

### What happened?

I am using the `kubectl-cnpg` plugin version `1.29.1`, installed via Krew.

```bash
kubectl cnpg version
```

Output:

```text
Build: {Version:1.29.1 Commit:a4060c152 Date:2026-05-08}
```

I wanted to generate an operator installation manifest for a previous supported CloudNativePG operator version with a custom namespace and replica count.

According to the documentation for `kubectl cnpg install generate --version`, it should be possible to specify a minor version like `1.28`, and the plugin should generate the latest patch version for that minor version.

However, the following commands fail:

```bash
kubectl cnpg install generate --version 1.28.3 --replicas 2 -n operators
kubectl cnpg install generate --version 1.28.3 -n operators
kubectl cnpg install generate --version 1.28.3

kubectl cnpg install generate --version 1.28.2 --replicas 2 -n operators
kubectl cnpg install generate --version 1.28.2 -n operators
kubectl cnpg install generate --version 1.28.2
```

Example error:

```text
Error: release version 1.28.3 not found
Error: exit status 1
```

Generating the manifest for the current plugin version works:

```bash
kubectl cnpg install generate --version 1.29.1 --replicas 2 -n operators
```

Generating the manifest for `1.28.1` also works:

```bash
kubectl cnpg install generate --version 1.28.1 --replicas 2 -n operators
```

This is confusing because `1.28.2` and `1.28.3` are newer patch versions in the same `1.28` minor line than `1.28.1`.

I also tried switching the plugin version via Krew. When using the `1.28.2` plugin version, generating `1.28.2` works. However, there is no `1.28.3` plugin version via krew (see https://github.com/kubernetes-sigs/krew-index/commits/843b1dc7d9e6d6300c2819f2961e88bcb38df5bc/plugins/cnpg.yaml ) so there seems to be no way to generate/install the `1.28.3` operator manifest with custom namespace and replicas using the Krew-installed `kubectl-cnpg` CLI.

Screenshot:

### Cluster resource

```shell

```

### Relevant log output

```shell

```

### Code of Conduct

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