feat: add realtime facade

Author: iBotPeaches

src/Facades/OpenAI.php

@@ -23,6 +23,7 @@
  * @method static \OpenAI\Resources\Images images()
  * @method static \OpenAI\Resources\Models models()
  * @method static \OpenAI\Resources\Moderations moderations()
+ * @method static \OpenAI\Resources\Realtime realtime()
  * @method static \OpenAI\Resources\Responses responses()
  * @method static \OpenAI\Resources\Threads threads()
  * @method static \OpenAI\Resources\VectorStores vectorStores()