Remove casting to int on increment ID which can be prefixed by a string

Author: sippsolutions

app/code/Magento/Sales/view/frontend/templates/order/print/invoice.phtml

@@ -14,7 +14,7 @@
 <?php foreach ($_invoices as $_invoice) : ?>
 <div class="order-details-items invoice">
     <div class="order-title">
-        <strong><?= $block->escapeHtml(__('Invoice #')) ?><?= (int) $_invoice->getIncrementId() ?></strong>
+        <strong><?= $block->escapeHtml(__('Invoice #')) ?><?= $_invoice->getIncrementId() ?></strong>
     </div>
     <div class="table-wrapper table-order-items invoice">
         <table class="data table table-order-items invoice" id="my-invoice-table-<?= (int) $_invoice->getId() ?>">