fix(metadata): operation NotExposed status to 404 (#5717)

Author: soyuka

src/Metadata/NotExposed.php

@@ -45,7 +45,7 @@ public function __construct(
         bool $stateless = null,
         string $sunset = null,
         string $acceptPatch = null,
-        $status = null,
+        $status = 404,
         string $host = null,
         array $schemes = null,
         string $condition = null,