test: align network approval test with runtime proxy config

codex-rs/core/tests/suite/approvals.rs

@@ -2234,7 +2234,10 @@ async fn denying_network_policy_amendment_persists_policy_and_skips_future_netwo
     let home = Arc::new(TempDir::new()?);
     fs::write(
         home.path().join("config.toml"),
-        r#"[permissions.network]
+        r#"[features]
+enable_network_proxy = true
+
+[permissions.network]
 mode = "limited"
 allow_local_binding = true
 "#,