Fix the dataconfig changes after 194a712

[mc-nya]

Hi
I got the running errors about missing field following the ReadMe tutorial.

pydantic_core._pydantic_core.ValidationError: 2 validation errors for DataConfig
train_configs
  Field required [type=missing, input_value={'vocab_size': 256, 'inpu...gs={'num_kv_pairs': 4})}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.4/v/missing
test_configs
  Field required [type=missing, input_value={'vocab_size': 256, 'inpu...gs={'num_kv_pairs': 4})}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.4/v/missing

It might caused by DataConfig update on commit 194a712, I updated the DataConfig in basic and basic_sweep, not sure it has the same behavior as previous code before DataConfig change.

[HardworkingPearl]

I get the same bug. does anyone know how to solve this?