Ensure deleted index data is integer IDs

With a very large product set (~213k) on 1 of our sites, the price index (and through the use of MSI, the inventory index) takes a very long time to complete, with multiple hours spent executing deleteIndexData. It seems the primary cause of this slowdown is string to int conversions or vice versa in MySQL, and ensuring that all IDs are integers beforehand yields much more consistent and reasonable performance on these larger sets

Author: nicka101

app/code/Magento/Catalog/Model/Indexer/Product/Price/AbstractAction.php

@@ -429,6 +429,7 @@ protected function _reindexRows($changedIds = [])
      */
     private function deleteIndexData(array $entityIds)
     {
+        $entityIds = array_unique(array_map('intval', $entityIds));
         foreach ($this->dimensionCollectionFactory->create() as $dimensions) {
             $select = $this->getConnection()->select()->from(
                 ['index_price' => $this->tableMaintainer->getMainTableByDimensions($dimensions)],