How to Disable Page Templates in Child Themes

<?php
add_filter( 'theme_page_templates', 'child_theme_remove_page_template' );
/**
* Remove page templates inherited from the parent theme.
*
* @param array $page_templates List of currently active page templates.
*
* @return array Modified list of page templates.
*/
function child_theme_remove_page_template( $page_templates ) {
    // Remove the template we don’t need.
    unset( $page_templates['template-full-width.php'] );

    return $page_templates;
}