feat(test): 移除 FileWatcher 中的 force_polling 参数，并添加等待时间以确保 watcher 建立基线

pytests/config_test/test_file_watcher.py

@@ -123,7 +123,7 @@ async def test_add_callback_while_watcher_running(tmp_path: Path):
     dirs.mkdir(exist_ok=True)
     file = (dirs / "a.toml").resolve()
     file.touch()
-    watcher = FileWatcher(paths=[dirs], debounce_ms=200, force_polling=True)
+    watcher = FileWatcher(paths=[dirs], debounce_ms=200)
 
     calls = 0
 
@@ -135,6 +135,7 @@ async def test_add_callback_while_watcher_running(tmp_path: Path):
     uuid = watcher.subscribe(callback, paths=[file])
     await watcher.start()
     try:
+        await asyncio.sleep(0.5)  # 等待 watcher 建立 baseline
         with file.open("w") as f:
             f.write("change")
         await _wait_for(lambda: calls >= 1)