EIP-7702: change `chain_id` type to `U256`

## Description Chain `chain_id` field type on `Authorization` to `U256`. https://github.com/alloy-rs/eips/blob/3e93f339daa4e51aed3767c76dd1c078532d8033/crates/eip7702/src/auth_list.rs#L49-L51 Reference: https://github.com/ethereum/EIPs/pull/9143