test(pleno-vue): queue two API responses for second ordering test too

tests/unit/order-content-table-addon-ordering.spec.js

@@ -210,6 +210,9 @@ describe("OrderContentTable addon ordering", () => {
         product: { id: 9, name: "Addon A" },
       },
     ];
+    // OrderContentTable mounts twice on initial render (immediate watcher plus
+    // a top-level call); queue two identical responses.
+    requestHolder.responses.push({ data: { data: apiResponse } });
     requestHolder.responses.push({ data: { data: apiResponse } });
 
     const wrapper = buildWrapper();