Non-required Card State

function pw_edd_remove_state_from_required_fields( $fields ) {

	if( array_key_exists( 'card_state', $fields ) ) {

		unset( $fields['card_state'] );

	}

	return $fields;

}

add_filter( 'edd_purchase_form_required_fields', 'pw_edd_remove_state_from_required_fields' );