fix(api/client): add validation for backup request body (#4704)

app/Http/Requests/Api/Client/Servers/Backups/RestoreBackupRequest.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Pterodactyl\Http\Requests\Api\Client\Servers\Backups;
+
+use Pterodactyl\Models\Permission;
+use Pterodactyl\Http\Requests\Api\Client\ClientApiRequest;
+
+class RestoreBackupRequest extends ClientApiRequest
+{
+    public function permission(): string
+    {
+        return Permission::ACTION_BACKUP_RESTORE;
+    }
+
+    public function rules(): array
+    {
+        return ['truncate' => 'required|boolean'];
+    }
+}