chore: use envoy gateway website instead of httpbin for test (envoyproxy#7371)

Signed-off-by: Huabing Zhao <[email protected]>
Signed-off-by: EkLine AI <[email protected]>

Author: zhaohuabing

internal/gatewayapi/testdata/securitypolicy-with-oidc-invalid-issuer.in.yaml

@@ -35,7 +35,7 @@ securityPolicies:
       name: gateway-1
     oidc:
       provider:
-        issuer: "https://httpbin.org/"
+        issuer: "https://gateway.envoyproxy.io"
       clientID: "client1.apps.foo.bar.com"
       clientSecret:
         name: "client1-secret"

internal/gatewayapi/testdata/securitypolicy-with-oidc-invalid-issuer.out.yaml

@@ -73,7 +73,7 @@ securityPolicies:
         kind: null
         name: client1-secret
       provider:
-        issuer: https://httpbin.org/
+        issuer: https://gateway.envoyproxy.io
     targetRef:
       group: gateway.networking.k8s.io
       kind: Gateway
@@ -87,7 +87,7 @@ securityPolicies:
         namespace: default
       conditions:
       - lastTransitionTime: null
-        message: 'OIDC: failed fetching openid-configuration from issuer URL: https://httpbin.org/,
+        message: 'OIDC: failed fetching openid-configuration from issuer URL: https://gateway.envoyproxy.io,
           status code: 404.'
         reason: Invalid
         status: "False"