Conflicting `NetworkWallet<Optimism>` impl for `EthereumWallet` with alloy 1.8

[suchapalaver]

Summary

op-alloy-network fails to compile against alloy 1.8 due to a conflicting NetworkWallet implementation.

Details

Alloy 1.8 introduced a blanket impl in alloy-network:

impl<N: Network> NetworkWallet<N> for EthereumWallet
where
    N::TxEnvelope: From<Signed<N::UnsignedTx>>,
    N::UnsignedTx: SignableTransaction<Signature>,
{ ... }

This conflicts with the manual impl in rust/op-alloy/crates/network/src/lib.rs:

impl NetworkWallet<Optimism> for EthereumWallet { ... }

The compiler error:

error[E0119]: conflicting implementations of trait `alloy_network::NetworkWallet<Optimism>` for type `alloy_network::EthereumWallet`

Proposed Fix

The manual impl can be safely removed because op-alloy-consensus already provides the trait bounds required by the blanket impl:

• OpTypedTransaction: SignableTransaction<Signature>
• OpTxEnvelope: From<Signed<OpTypedTransaction>>

The blanket impl delegates signing to SignableTransaction::sign_transaction + into_signed, which produces the same result as the manual variant-by-variant conversion.

The unused imports and the alloy-signer dependency should also be removed as they are only used by the manual impl.

(Previously filed as alloy-rs/op-alloy#627 before the repo was upstreamed.)