Below is a PHP function that can programmatically logout or destroy a user session in WordPress taking the user ID as an argument.
/**
* Destroy the session of a user.
*
* @param int $user_id
*/
function pp_destroy_user_session( $user_id ) {
// get all sessions for user with ID $user_id
$sessions = WP_Session_Tokens::get_instance( $user_id );
// we have got the sessions, destroy them all!
$sessions->destroy_all();
}