Add Guard Clause to check if invoice has been canceled previously

Author: osrecio

app/code/Magento/Sales/Model/Order/Invoice.php

@@ -407,6 +407,10 @@ public function void()
      */
     public function cancel()
     {
+        if (!$this->canCancel()) {
+            return $this;
+        }
+        
         $order = $this->getOrder();
         $order->getPayment()->cancelInvoice($this);
         foreach ($this->getAllItems() as $item) {