tree-wide: Sort includes

This was done by running a locally built clang-format with
https://github.com/llvm/llvm-project/pull/137617 and
https://github.com/llvm/llvm-project/pull/137840 applied on all .c
and .h files.

src/nspawn/nspawn-bind-user.h

@@ -1,9 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "user-record.h"
 #include "group-record.h"
 #include "nspawn-mount.h"
+#include "user-record.h"
 
 typedef struct BindUserData {
         /* The host's user/group records */