chore: add missing ClientFake for containers

Author: iBotPeaches

src/Testing/ClientFake.php

@@ -13,6 +13,7 @@
 use OpenAI\Testing\Resources\BatchesTestResource;
 use OpenAI\Testing\Resources\ChatTestResource;
 use OpenAI\Testing\Resources\CompletionsTestResource;
+use OpenAI\Testing\Resources\ContainersTestResource;
 use OpenAI\Testing\Resources\EditsTestResource;
 use OpenAI\Testing\Resources\EmbeddingsTestResource;
 use OpenAI\Testing\Resources\FilesTestResource;
@@ -154,6 +155,11 @@ public function chat(): ChatTestResource
         return new ChatTestResource($this);
     }
 
+    public function containers(): ContainersTestResource
+    {
+        return new ContainersTestResource($this);
+    }
+
     public function embeddings(): EmbeddingsTestResource
     {
         return new EmbeddingsTestResource($this);