Indexing fails for partial splits
because it tries to get the parquet files from the e.g. `config/train` directory instead of `config/partial-train`.

Some impacted datasets: common voice 11, c4
Indexing fails for partial splits: because it tries to get the parquet files from the e.g. `config/train` directory instead of `config/partial-train`.

Some impacted datasets: common voice 11, c4