Fixes for build output tables

- Only show "completed" builds in the "completed builds" table (should be obvious)
- Display "serial number" appropriately in build output allocation table

InvenTree/build/templates/build/detail.html

@@ -292,6 +292,7 @@ loadStockTable($("#build-stock-table"), {
         location_detail: true,
         part_detail: true,
         build: {{ build.id }},
+        is_building: false,
     },
     groupByField: 'location',
     buttons: [