chore(admin-ui): add key for gift-cards table cells map fn (#6154)

![image](https://github.com/medusajs/medusa/assets/24707417/e13ff43b-770e-4698-bb9a-e22b866069f6)

packages/admin-ui/ui/src/components/templates/gift-card-table/index.tsx

@@ -184,7 +184,7 @@ const GiftCardTable = () => {
                   className="group"
                 >
                   {row.cells.map((cell, index) => {
-                    return cell.render("Cell", { index })
+                    return cell.render("Cell", { index, key: index })
                   })}
                 </Table.Row>
               )