fn default() -> Self {
        Self::V1(FeeModelConfigV1 {
            minimal_l2_gas_price: 100_000_000,
        })
    }
Config with all zeroes is not a valid config (since for instance having 0 max gas per batch may incur division by zero),
so we implement a sensible default config here.
core/lib/types/src/fee_model.rs