Fix CDN caching test

We should do multiple requests to check that the initial request is
cached. Otherwise a single request within a 5 min window will be
uncached.

tests/cdn.spec.js

@@ -47,6 +47,7 @@ test.describe("CDN", () => {
   });
 
   test("Check caching behaviour for GET requests", { tag: ["@notcloudfront"] }, async ({ page }) => {
+    await page.request.get("/");
     const response = await page.request.get("/");
     expect(parseInt(response.headers()["x-cache-hits"])).toBeGreaterThan(0);
   });