Fix "CVV" label pointing to wrong field (#25518)

Author: ysds

docs/4.0/examples/checkout/index.html

@@ -211,7 +211,7 @@ <h4 class="mb-3">Payment</h4>
                 </div>
               </div>
               <div class="col-md-3 mb-3">
-                <label for="cc-expiration">CVV</label>
+                <label for="cc-cvv">CVV</label>
                 <input type="text" class="form-control" id="cc-cvv" placeholder="" required>
                 <div class="invalid-feedback">
                   Security code required