magento-test/app/code/Magento/CatalogSearch/etc/db_schema.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<schema xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:Setup/Declaration/Schema/etc/schema.xsd">
    <table name="catalog_eav_attribute" resource="default" comment="Catalog EAV Attribute Table">
        <column xsi:type="float" name="search_weight" unsigned="false" nullable="false"
                default="1" comment="Search Weight"/>
    </table>
</schema>