Deprecation note to the Multiplexer tutorial (#338)

Author: bilgeyucel

index.toml

@@ -411,6 +411,7 @@ aliases = []
 completion_time = "10 min"
 created_at = 2024-02-19
 haystack_2 = true
+haystack_version = "2.3.1"
 dependencies = ["transformers", "huggingface_hub>=0.22.0"]
 
 [[tutorial]]

tutorials/37_Simplifying_Pipeline_Inputs_with_Multiplexer.ipynb

@@ -15,6 +15,8 @@
     "- **Prerequisites**: You must have a [Hugging Face API Key](https://huggingface.co/settings/tokens) and be familiar with [creating pipelines](https://docs.haystack.deepset.ai/docs/creating-pipelines)\n",
     "- **Goal**: After completing this tutorial, you'll have learned how to use a Multiplexer to simplify the inputs that `Pipeline.run()` get\n",
     "\n",
+    "> As of version 2.2.0, `Multiplexer` has been deprecated in Haystack and will be completely removed from Haystack as of v2.4.0. We recommend using [BranchJoiner](https://docs.haystack.deepset.ai/docs/branchjoiner) instead. For more details about this deprecation, check out [Haystack 2.2.0 release notes](https://github.com/deepset-ai/haystack/releases/tag/v2.2.0) on Github.\n",
+    "\n",
     "> This tutorial uses Haystack 2.0. To learn more, read the [Haystack 2.0 announcement](https://haystack.deepset.ai/blog/haystack-2-release) or visit the [Haystack 2.0 Documentation](https://docs.haystack.deepset.ai/docs/intro)."
    ]
   },