Apisix-ingress-controller chart missing HPA template — autoscaling values have no effect

Chart version: apisix-ingress-controller v1.2.0
Controller version: 2.1.0

The chart's values.yaml documents an autoscaling block:

```
autoscaling:
enabled: true
minReplicas: 2
maxReplicas: 3
targetCPUUtilizationPercentage: 80
targetMemoryUtilizationPercentage: 80
```

However, there is no corresponding hpa.yaml template in charts/apisix-ingress-controller/templates/. As a result, enabling autoscaling has no effect — no HorizontalPodAutoscaler is created and the deployment stays at deployment.replicas (default 1).

The apisix chart (same repo) does include templates/hpa.yaml and renders an HPA correctly. Could the same template be added for the ingress controller chart?

Start with charts/apisix-ingress-controller/values.yaml and inspect the existing apisix chart templates/hpa.yaml as the reference. Render the ingress-controller chart with autoscaling enabled and verify that it produces a HorizontalPodAutoscaler using the configured replica and utilization values.

Written by the indexing model from the issue text.