fix(payload): Ethereum Payload Builder Zero Type (#5313)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

crates/payload/basic/src/lib.rs

@@ -62,9 +62,14 @@ mod optimism;
 #[cfg(feature = "optimism")]
 pub use optimism::OptimismPayloadBuilder;
 
+/// Ethereum payload builder
+#[derive(Debug, Clone, Copy, Default)]
+#[non_exhaustive]
+pub struct EthereumPayloadBuilder;
+
 /// The [`PayloadJobGenerator`] that creates [`BasicPayloadJob`]s.
 #[derive(Debug)]
-pub struct BasicPayloadJobGenerator<Client, Pool, Tasks, Builder = ()> {
+pub struct BasicPayloadJobGenerator<Client, Pool, Tasks, Builder = EthereumPayloadBuilder> {
     /// The client that can interact with the chain.
     client: Client,
     /// txpool
@@ -94,7 +99,14 @@ impl<Client, Pool, Tasks> BasicPayloadJobGenerator<Client, Pool, Tasks> {
         config: BasicPayloadJobGeneratorConfig,
         chain_spec: Arc<ChainSpec>,
     ) -> Self {
-        BasicPayloadJobGenerator::with_builder(client, pool, executor, config, chain_spec, ())
+        BasicPayloadJobGenerator::with_builder(
+            client,
+            pool,
+            executor,
+            config,
+            chain_spec,
+            EthereumPayloadBuilder,
+        )
     }
 }
 
@@ -716,7 +728,7 @@ pub trait PayloadBuilder<Pool, Client>: Send + Sync + Clone {
 }
 
 // Default implementation of [PayloadBuilder] for unit type
-impl<Pool, Client> PayloadBuilder<Pool, Client> for ()
+impl<Pool, Client> PayloadBuilder<Pool, Client> for EthereumPayloadBuilder
 where
     Client: StateProviderFactory,
     Pool: TransactionPool,

crates/payload/basic/src/optimism.rs

@@ -287,7 +287,8 @@ where
 }
 
 /// Optimism's payload builder
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy, Default)]
+#[non_exhaustive]
 pub struct OptimismPayloadBuilder;
 
 /// Implementation of the [PayloadBuilder] trait for [OptimismPayloadBuilder].