您的参数不匹配,即您尝试为用户类型指定Long作为参数:
您可以通过以下两种方式之一对其进行更改:
@Query("DELETE FROM Collaborator c WHERE c.user.id = :userId AND c.task.id = :taskId")
void deleteUserFromTask(@Param("userId") Long userId, @Param("taskId") Long taskId);
要么
@Query("DELETE FROM Collaborator c WHERE c.user = :user AND c.task = :task")
void deleteUserFromTask(@Param("user") User user, @Param("task") Task task);