[Graphbolt][Cleanup] Remove old code after seeds refactor

## 🔨Work Item

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Project tracker: https://github.com/orgs/dmlc/projects/2

## Description
The [Datasets](https://github.com/dmlc/dgl/blob/master/python/dgl/graphbolt/impl/ondisk_dataset.py#L1006) that have no "-seeds" BuiltinDataset in the onDiskDataset.py that are not used anymore. We need to remove them.

Moreover, any code that needs to be removed after the seeds refactoring needs to be considered.

## Depending work items or issues