disable use_future on the server

packages/core/src/virtual_dom.rs

@@ -448,6 +448,8 @@ impl VirtualDom {
 
             // Hold a lock to the flush sync to prevent tasks from running in the event we get an immediate
             // When we're doing awaiting the rx, the lock will be dropped and tasks waiting on the lock will get waked
+            // We have to own the lock since poll_tasks is cancel safe - the future that this is running in might get dropped
+            // and if we held the lock in the scope, the lock would also get dropped prematurely
             self.runtime.acquire_flush_lock();
 
             match self.rx.next().await.expect("channel should never close") {