test(exex): improve PollOnce trait error handling (#8653)

examples/exex/minimal/src/main.rs

@@ -60,7 +60,7 @@ mod tests {
     use reth_exex_test_utils::{test_exex_context, PollOnce};
 
     #[tokio::test]
-    async fn exex() -> eyre::Result<()> {
+    async fn test_exex() -> eyre::Result<()> {
         // Initialize a test Execution Extension context with all dependencies
         let (ctx, mut handle) = test_exex_context().await?;
 
@@ -83,7 +83,7 @@ mod tests {
         handle.assert_events_empty();
 
         // Poll the Execution Extension once to process incoming notifications
-        exex.poll_once().await;
+        exex.poll_once().await?;
 
         // Check that the Execution Extension emitted a `FinishedHeight` event with the correct
         // height