[BUG] algos.ipynb does its own train-validation split?

[lovettchris]

Describe the bug

Why is this:

        # Loads the dataset
        tr_data = dataset_provider.get_train_dataset()
        
        # Train-validation split
        tr_data, val_data = torch.utils.data.random_split(
            tr_data, lengths=[len(tr_data) - 1_000, 1_000], 
            generator=torch.Generator().manual_seed(42)
        )

not just this?

        # Loads the datasets
        tr_data = dataset_provider.get_train_dataset()
        val_data = dataset_provider.get_val_dataset()

[gugarosa]

These notebooks were written prior the new DatasetProvider abstraction. At that time, we had to manually create the validation split because the old abstraction did not have support for it.

I will fix it.