chore(engine): remove biased select in engine service loop (#21961)

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: joshieDo <93316087+joshieDo@users.noreply.github.com>

.changelog/lazy-lakes-shout.md

@@ -0,0 +1,5 @@
+---
+reth-node-builder: patch
+---
+
+Removed biased select in engine service loop to allow fair scheduling of shutdown requests alongside event processing.

crates/node/builder/src/launch/engine.rs

@@ -303,8 +303,6 @@ impl EngineNodeLauncher {
             // the CL
             loop {
                 tokio::select! {
-                    biased;
-
                     event = engine_service.next() => {
                         let Some(event) = event else { break };
                         debug!(target: "reth::cli", "Event: {event}");