Extension Server Fail Closed: ready route

*Description*:
When the post-translate hook is executed, all dynamic listener (incl. ready listener) are updated with a 500 direct response. This leads to k8s probe failures.

*Logs*:
Readiness listener after fail closed:

```sh
"dynamic_listeners": [
{
"name": "envoy-gateway-proxy-ready-0.0.0.0-19003",
"active_state": {
"version_info": "480eb87881317ebff21162f54e4a9c59c648d67a93fb17232e909ed08547e473",
"listener": {
"@type": "type.googleapis.com/envoy.config.listener.v3.Listener",
"name": "envoy-gateway-proxy-ready-0.0.0.0-19003",
"address": {
"socket_address": {
"address": "0.0.0.0",
"port_value": 19003
}
},
"filter_chains": [
{
"filters": [
{
"name": "envoy.filters.network.http_connection_manager",
"typed_config": {
"@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
"stat_prefix": "eg-ready-http",
"route_config": {
"name": "error_route_configuration",
"virtual_hosts": [
{
"name": "error_vhost",
"domains": [
"*"
],
"routes": [
{
"match": {
"prefix": "/"
},
"direct_response": {
"status": 500
},
"name": "error_route"
}
]
}
]
},
"http_filters": [
{
"name": "envoy.filters.http.health_check",
"typed_config": {
"@type": "type.googleapis.com/envoy.extensions.filters.http.health_check.v3.HealthCheck",
"pass_through_mode": false,
"headers": [
{
"name": ":path",
"string_match": {
"exact": "/ready"
}
}
]
}
},
{
"name": "envoy.filters.http.router",
"typed_config": {
"@type": "type.googleapis.com/envoy.extensions.filters.http.router.v3.Router",
"suppress_envoy_headers": true
}
}
]
}
}
]
}
],
"bypass_overload_manager": true
},
"last_updated": "2025-03-24T23:30:39.154Z"
```