fix "coroutine 'sleep' was never awaited"

Author: jinzhen-lin

python_packages/jupyter_lsp/jupyter_lsp/manager.py

@@ -127,7 +127,7 @@ def initialize(self, *args, **kwargs):
 
     async def ready(self):
         while not self._ready:  # pragma: no cover
-            asyncio.sleep(0.1)
+            await asyncio.sleep(0.1)
         return True
 
     def init_language_servers(self) -> None: