how to increase sku 64 symbols to be 255 symbols at magento 2.3.2

by |Published April 10, 2020

how to increase sku 64 symbols to be 255 symbols at magento 2.3.2
the below image
https://i.imgur.com/MaWo0Qo.jpg

i did this but still same
set “const SKU_MAX_LENGTH = 255;” in the file module-catalog/Model/Product/Attribute/Backend/Sku.php
SQL
ALTER TABLE catalog_product_entity CHANGE sku sku VARCHAR(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT ‘SKU’;