shared: Clean up includes

Split out of #37344.

src/shared/condition.h

@@ -1,12 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include <errno.h>
-#include <stdbool.h>
-#include <stdio.h>
-
 #include "list.h"
-#include "macro.h"
+#include "forward.h"
 
 typedef enum ConditionType {
         CONDITION_ARCHITECTURE,