Fix AuthorizationClientIPTrustedCidrsTest on IPv6 Cluster

[arkodg]

Description:

What issue is being seen? Describe what should be happening instead of
the bug, for example: Envoy should not crash, the expected value isn't
returned, etc.

est failure: https://github.com/envoyproxy/gateway/actions/runs/12772899958/job/35604351424

roundtripper.go:235: 2025-01-14T21:24:46.292659177Z: Received Response:
2025-01-14T21:24:46.2930635Z < HTTP/1.1 200 OK
2025-01-14T21:24:46.2931136Z < Connection: close
2025-01-14T21:24:46.2931758Z < Content-Length: 687
2025-01-14T21:24:46.2932095Z < Content-Type: application/json
2025-01-14T21:24:46.2932454Z < Date: Tue, 14 Jan 2025 21:24:46 GMT
2025-01-14T21:24:46.2932821Z < X-Content-Type-Options: nosniff
2025-01-14T21:24:46.2933092Z <
2025-01-14T21:24:46.2933300Z < {
2025-01-14T21:24:46.2933548Z < "path": "/protected1",
2025-01-14T21:24:46.2934231Z < "host": "[fc00:f853:ccd:e793::cb]",
2025-01-14T21:24:46.2934544Z < "method": "GET",
2025-01-14T21:24:46.2934818Z < "proto": "HTTP/1.1",
2025-01-14T21:24:46.2935081Z < "headers": {
2025-01-14T21:24:46.2935349Z < "Accept-Encoding": [
2025-01-14T21:24:46.2935606Z < "gzip"
2025-01-14T21:24:46.2935806Z < ],
2025-01-14T21:24:46.2936042Z < "Traceparent": [
2025-01-14T21:24:46.2936463Z < "00-bfd70f0c7e9b33339ca55605fab227bd-de31131cfbf520a5-01"
2025-01-14T21:24:46.2936794Z < ],
2025-01-14T21:24:46.2937022Z < "Tracestate": [
2025-01-14T21:24:46.2937248Z < ""
2025-01-14T21:24:46.2937445Z < ],
2025-01-14T21:24:46.2937670Z < "User-Agent": [
2025-01-14T21:24:46.2937953Z < "Go-http-client/1.1"
2025-01-14T21:24:46.2938197Z < ],
2025-01-14T21:24:46.2938442Z < "X-Echo-Set-Header": [
2025-01-14T21:24:46.2938692Z < ""
2025-01-14T21:24:46.2938892Z < ],
2025-01-14T21:24:46.2939132Z < "X-Forwarded-For": [
2025-01-14T21:24:46.2939527Z < "192.168.2.1,192.168.1.1,10.0.1.12,fc00:f853:ccd:e793::1"
2025-01-14T21:24:46.2939840Z < ],
2025-01-14T21:24:46.2940094Z < "X-Forwarded-Proto": [
2025-01-14T21:24:46.2940354Z < "http"
2025-01-14T21:24:46.2940553Z < ],
2025-01-14T21:24:46.2940788Z < "X-Request-Id": [
2025-01-14T21:24:46.2941121Z < "4f8d83f2-a7e3-9192-a4cb-1779b70549ed"
2025-01-14T21:24:46.2941643Z < ]
2025-01-14T21:24:46.2941842Z < },
2025-01-14T21:24:46.2942153Z < "namespace": "gateway-conformance-infra",
2025-01-14T21:24:46.2942474Z < "ingress": "",
2025-01-14T21:24:46.2942931Z < "service": "infra-backend-v1",
2025-01-14T21:24:46.2943340Z < "pod": "infra-backend-v1-7d4b69fd5d-p6722"
2025-01-14T21:24:46.2943642Z < }
2025-01-14T21:24:46.2943944Z
2025-01-14T21:24:46.2944126Z
2025-01-14T21:24:46.2946233Z http.go:240: 2025-01-14T21:24:46.292731572Z: Response expectation failed for request: {URL: {Scheme:http Opaque: User: Host:[fc00:f853:ccd:e793::cb] Path:/protected1 RawPath: OmitHost:false ForceQuery:false RawQuery: Fragment: RawFragment:}, Host: , Protocol: HTTP, Method: GET, Headers: map[X-Echo-Set-Header:[] X-Forwarded-For:[192.168.2.1,192.168.1.1,10.0.1.12]], UnfollowRedirect: false, Server: , CertPem: , KeyPem: } not ready yet: expected status code to be 403, got 200 (after 1.001606046s)
Relates to #4702

Repro steps:

Include sample requests, environment, etc. All data and inputs
required to reproduce the bug.

Note: If there are privacy concerns, sanitize the data prior to
sharing.

Environment:

Include the environment like gateway version, envoy version and so on.

Logs:

Include the access logs and the Envoy logs.

[arkodg]

cc @rudrakhp