chore(node): Remove version sync task (#2125)

## What ❔

Removes the version sync task from EN.

## Why ❔

The migration was completed a while ago.

## Checklist

<!-- Check your PR fulfills the following items. -->
<!-- For draft PRs check the boxes as you complete them. -->

- [ ] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [ ] Tests for the changes have been added / updated.
- [ ] Documentation comments have been added / updated.
- [ ] Code has been formatted via `zk fmt` and `zk lint`.
- [ ] Spellcheck has been run via `zk spellcheck`.

core/bin/external_node/src/main.rs

@@ -66,7 +66,6 @@ mod metadata;
 mod metrics;
 #[cfg(test)]
 mod tests;
-mod version_sync_task;
 
 /// Creates the state keeper configured to work in the external node mode.
 #[allow(clippy::too_many_arguments)]
@@ -913,20 +912,7 @@ async fn run_node(
     );
     let validate_chain_ids_task = tokio::spawn(validate_chain_ids_task.run(stop_receiver.clone()));
 
-    let version_sync_task_pool = connection_pool.clone();
-    let version_sync_task_main_node_client = main_node_client.clone();
-    let mut stop_receiver_for_version_sync = stop_receiver.clone();
-    let version_sync_task = tokio::spawn(async move {
-        version_sync_task::sync_versions(
-            version_sync_task_pool,
-            version_sync_task_main_node_client,
-        )
-        .await?;
-
-        stop_receiver_for_version_sync.changed().await.ok();
-        Ok(())
-    });
-    let mut task_handles = vec![metrics_task, validate_chain_ids_task, version_sync_task];
+    let mut task_handles = vec![metrics_task, validate_chain_ids_task];
     task_handles.extend(prometheus_task);
 
     // Make sure that the node storage is initialized either via genesis or snapshot recovery.