Helm Chart V2: RoleBinding missing namespace in subjects causes 401 Unauthorized

### Helm Chart Version

2.0.19 (appVersion 2.0.0)

### What step the error happened?

Upgrading the Platform or Helm Chart

### Relevant information

The `serviceaccount.yaml` template creates a RoleBinding without specifying `namespace` in the `subjects[]` array. This causes 401 Unauthorized errors when pods try to use the ServiceAccount after RBAC resources are recreated (e.g., during upgrades or when namespace labels change via Terraform).

**Current code** in `templates/serviceaccount.yaml` (line 43-45):

```yaml
subjects:
- kind: ServiceAccount
name: {{ include "airbyte.serviceAccountName" . }}
```

**Fix** - add `namespace`:

```yaml
subjects:
- kind: ServiceAccount
name: {{ include "airbyte.serviceAccountName" . }}
namespace: {{ .Release.Namespace }}
```

**Steps to reproduce:**

1. Deploy Airbyte with Helm Chart V2 (2.0.19) on GKE
2. Trigger RBAC recreation (e.g., Terraform apply that modifies namespace labels, or Helm upgrade)
3. Observe workload-launcher pod logs showing 401 Unauthorized when listing/creating pods

**Workaround:** Adding `namespace: {{ .Release.Namespace }}` to subjects and restarting affected pods resolves the issue.

**Environment:**

- Kubernetes: GKE 1.33
- Helm Chart: V2 2.0.19
- Airbyte: 2.0.0 (community edition)
- Deployment method: Kustomize + ArgoCD

### Relevant log output

```shell
io.fabric8.kubernetes.client.KubernetesClientException:
Failure executing: GET at: https://kubernetes.default.svc/api/v1/namespaces/airbyte/pods
Message: Unauthorized
```

---
**Internal Tracking:** https://github.com/airbytehq/oncall/issues/11238