fix: ecosystem-level default in config for local gas limit

[antazoey]

What I did

this helps Arbitrum utilize the new base class and others who may change the default utilize the base class

class ArbitrumConfig(BaseEthereumConfig):
    DEFAULT_TRANSACTION_TYPE: ClassVar[int] = EthTransactionType.STATIC.value
    DEFAULT_LOCAL_GAS_LIMIT: ClassVar[GasLimit] = LOCAL_GAS_LIMIT
    mainnet: NetworkConfig = _create_config()
    goerli: NetworkConfig = _create_config()
    sepolia: NetworkConfig = _create_config()

see Arby PR: ApeWorX/ape-arbitrum#27

How I did it

classvar default

How to verify it

Checklist

• All changes are completed
• New test cases have been added
• Documentation has been updated

[antazoey]

This is the last PR I need to get custom networks config working across all our L2 plugins