/**
 * Disables pingbacks from your own site.
 */
add_action( 'pre_ping', function ( &$post_links, &$pung, int $post_ID ) {
	foreach ( $post_links as $key => $link ) {
		if ( 0 === strpos( $link, home_url() ) ) {
			unset( $post_links[ $key ] );
		}
	}
}, 10, 3 );