fix: manual timer deadline resolution (#1273)

It seems sometimes Tokio's timer wheel may not advance (if the executor
is blocked) causing `Sleep` future to take more ticks to be woken up and
be `Poll::Ready` even after deadline passes. This fix adds an early
deadline check in `MutableSleep::poll_ready`.

```js
let ticked = false;
setTimeout(() => {
  console.log("timer done");
  ticked = true;
}, 1);
const now = Date.now();
while (Date.now() - now < 2);

setImmediate(() => {
  console.log(ticked); // true
});
```

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

Author: littledivy

core/web_timeout.rs

@@ -180,6 +180,19 @@ impl MutableSleep {
         if !external.will_wake(waker) {
           external.clone_from(waker);
         }
+
+        // We do a manual deadline check here. Tokio's timer wheel may not immediately check the deadline if the
+        // executor was blocked.
+        // Skip this check under Miri as it interferes with time simulation.
+        #[cfg(not(miri))]
+        {
+          let sleep = unsafe { self.sleep.get().as_mut().unwrap_unchecked() };
+          if let Some(sleep) = sleep
+            && Instant::now() >= sleep.deadline()
+          {
+            return Poll::Ready(());
+          }
+        }
         Poll::Pending
       } else {
         *external = Some(cx.waker().clone());