Implement empty return for getItems in FakeErrorCache

Modified the getItems method to return an empty array for better consistency and predictability within test simulations. This change ensures that the method adheres to the expected interface behavior during testing.

tests/Fake/FakeErrorCache.php

@@ -19,6 +19,7 @@ public function getItem($key): CacheItem
 
     public function getItems(array $keys = []): iterable
     {
+        return [];
     }
 
     public function hasItem($key): bool