Remove `Section` record since it is not useful

[scastd]

Describe the feature

Variables cannot be passed directly to a specific section in the OpenMP standard; they can only be passed within the "global" construct.

❌ Disallowed:

#pragma omp parallel sections
{
    #pragma omp section shared(x, y)
    {
        printf("Task 1. Running thread %d\n", omp_get_thread_num());
    }
}

✅ Allowed:

#pragma omp parallel sections shared(x, y)
{
    #pragma omp section
    {
        printf("Task 1. Running thread %d\n", omp_get_thread_num());
    }
}

Additional information

• [X] Would you be willing to help implement this feature?

Final checks

• [X] Read the contribution guide.
• [X] Check existing discussions and issues.