io/uring/Handler: remove unused header

src/io/uring/Handler.hxx

@@ -1,21 +0,0 @@
-// SPDX-License-Identifier: BSD-2-Clause
-// Copyright CM4all GmbH
-// author: Max Kellermann <mk@cm4all.com>
-
-#pragma once
-
-#include <exception>
-
-struct statx;
-class UniqueFileDescriptor;
-
-namespace Uring {
-
-class OpenStatHandler {
-public:
-	virtual void OnOpenStat(UniqueFileDescriptor fd,
-				struct statx &st) noexcept = 0;
-	virtual void OnOpenStatError(std::exception_ptr e) noexcept = 0;
-};
-
-} // namespace Uring