Remove the category taxonomy drop down from the posts lists table in WordPress Admin (edit.php)

Remove Category Dropdown

<?php

/**
 * Remove the category taxonomy drop down from the posts lists table
 * 
 * @param string $output The resulting HTML to build the select dropdown
 * @param array $r The array of arguments to build the select dropdown
 *
 * @return string $output The filtered HTML of the dropdown
 */
 
function db_remove_category_dropdown($output, $r ){
    global $pagenow;
    if( 'category' === $r['taxonomy']  && 'edit.php' === $pagenow ){
        $output = '';
    }
    return $output;
}
	
add_filter('wp_dropdown_cats', 'db_remove_category_dropdown', 0, 2);