Prevent extra arguments to Dataset classes

[danbraunai-apollo]

We currently have e.g.

class ModularArithmeticDatasetConfig(BaseModel):
    """Config for the modular arithmetic dataset.

    We set fields to optional so that we have the option of loading them in from a pre-saved config
    file (see `rib/loader.create_modular_arithmetic_dataset`)
    """

    source: Literal["custom"] = "custom"
    name: Literal["modular_arithmetic"] = "modular_arithmetic"
    return_set: Literal["train", "test", "all", "both"] = Field(
        ...,
        description="The dataset to return. If 'both', returns both the train and test datasets."
        "If 'all', returns the combined train and test datasets.",
    )
    modulus: Optional[int] = Field(None, description="The modulus to use for the dataset.")
    fn_name: Optional[Literal["add", "subtract", "x2xyy2"]] = Field(
        None,
        description="The function to use for the dataset. One of 'add', 'subtract', or 'x2xyy2'.",
    )
    frac_train: Optional[float] = Field(
        None, description="Fraction of the dataset to use for training."
    )
    seed: Optional[int] = Field(None, description="The random seed value for reproducibility.")

But this doesn't prevent one from passing extra arguments like "return_set_frac" to this class. We would like it to prevent this.

We just need model_config = ConfigDict(extra="forbid") in all the relevant classes (I think probably every pydantic class)

[nix-apollo]

Agree forbidding extra arguments is probably good. Sometimes it will mess things up if we remove config arguments then try to load old configs, but I think we don't care very much.

Separately, it would be nice if modular arithmetic dataset supported these arguments, but that's another issue.