Address review feedback.

src/textual/_time.py

@@ -1,5 +1,5 @@
-import platform
 import asyncio
+import platform
 from asyncio import sleep as asyncio_sleep
 from time import monotonic, perf_counter
 
@@ -26,7 +26,9 @@ async def sleep(secs: float) -> None:
         Args:
             secs: Number of seconds to sleep for.
         """
-        await asyncio.create_task(win_sleep(secs))
+        sleep = win_sleep(secs)
+        if sleep is not None:
+            await asyncio.create_task(sleep)
 
 else:
 

src/textual/_win_sleep.py

@@ -4,6 +4,8 @@
 This should only be imported on Windows.
 """
 
+from __future__ import annotations
+
 import asyncio
 from time import sleep as time_sleep
 from typing import Coroutine
@@ -35,7 +37,7 @@ def sleep(secs: float) -> Coroutine[None, None, None]:
 
 else:
 
-    def sleep(secs: float) -> Coroutine[None, None, None]:
+    def sleep(secs: float) -> Coroutine[None, None, None] | None:
         """A replacement sleep for Windows.
 
         Note that unlike `time.sleep` this *may* sleep for slightly less than the
@@ -49,7 +51,7 @@ def sleep(secs: float) -> Coroutine[None, None, None]:
         sleep_for = max(0, secs - 0.001)
         if sleep_for < 0.0005:
             # Less than 0.5ms and its not worth doing the sleep
-            return time_sleep_coro(0)
+            return None
 
         timer = kernel32.CreateWaitableTimerExW(
             None,