question: Plan for supporting Gateway API Experimental ExternalAuth filter?

*Description*:
Is there a plan to implement the HTTPRoute `ExternalAuth` filter (Gateway API experimental channel)?

```yaml
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
name: auth
spec:
parentRefs:
- name: eg
rules:
- matches:
- path:
type: Exact
value: /api.auth.v1.Authn/Login
backendRefs:
- name: auth-svc
port: 8080
- matches:
- path:
type: Exact
value: /api.auth.v1.Authn/Logout
filters:
- type: ExternalAuth
externalAuth:
protocol: HTTP
backendRef:
name: auth-svc
port: 8080
http:
path: /api.auth.v1.Session/Validate
backendRefs:
- name: auth-svc
port: 8080
```

[optional *Relevant Links*:]
https://kubernetes.io/blog/2025/11/06/gateway-api-v1-4/#enabling-external-auth-for-httproute