ignore mypy error

Author: Zsailer

jupyter_client/multikernelmanager.py

@@ -217,7 +217,7 @@ async def _async_start_kernel(self, kernel_name: t.Optional[str] = None, **kwarg
             await fut
             # raise an exception if one occurred during kernel startup.
             if km.ready.exception():
-                raise km.ready.exception()
+                raise km.ready.exception()  # type: ignore
 
         return kernel_id