tc-core-update-minor.php

<?php
/**
 * Plugin Name:     Set Auto Updates to minor only
 * Plugin URI:      https://tadpole.cc
 * Description:     Allow automatic updates for security releases only 
 * Author:          Kevin Cristiano
 * Author URI:      https://tadpole.cc
 * Text Domain:     tc-core-update-minor
 * Domain Path:     /languages
 * Version:         0.1.0
 *
 * @package         Tc_Core_Update_Minor
 */

add_filter( 'allow_major_auto_core_updates', '__return_false' );