Sensei: Allow teachers to grade all quizzes

gistfile1.php

add_filter('sensei_check_for_activity', 'sensei_allow_teachers_to_grade_all_quizzes', 5 );

function sensei_allow_teachers_to_grade_all_quizzes( $args ){

    // remove the limit
    remove_filter( 'sensei_check_for_activity' , array( Sensei()->teacher, 'filter_grading_activity_queries') );

    // make sure to the return the expected arguments
    return $args;

}