chore(payload-builder): relax Sync bounds on resolve futures (#18585)

crates/payload/builder/src/service.rs

@@ -30,7 +30,7 @@ use tokio::sync::{
 use tokio_stream::wrappers::UnboundedReceiverStream;
 use tracing::{debug, info, trace, warn};
 
-type PayloadFuture<P> = Pin<Box<dyn Future<Output = Result<P, PayloadBuilderError>> + Send + Sync>>;
+type PayloadFuture<P> = Pin<Box<dyn Future<Output = Result<P, PayloadBuilderError>> + Send>>;
 
 /// A communication channel to the [`PayloadBuilderService`] that can retrieve payloads.
 ///

crates/payload/builder/src/traits.rs

@@ -23,7 +23,6 @@ pub trait PayloadJob: Future<Output = Result<(), PayloadBuilderError>> {
     /// Represents the future that resolves the block that's returned to the CL.
     type ResolvePayloadFuture: Future<Output = Result<Self::BuiltPayload, PayloadBuilderError>>
         + Send
-        + Sync
         + 'static;
     /// Represents the built payload type that is returned to the CL.
     type BuiltPayload: BuiltPayload + Clone + std::fmt::Debug;