docs: fixed a typo (#28191)

**Description**: removed the redundant phrase (typo)

docs/docs/tutorials/llm_chain.ipynb

@@ -318,7 +318,7 @@
    "source": [
     "## Conclusion\n",
     "\n",
-    "That's it! In this tutorial you've learned how to create your first simple LLM application. You've learned how to work with language models, how to how to create a prompt template, and how to get great observability into chains you create with LangSmith.\n",
+    "That's it! In this tutorial you've learned how to create your first simple LLM application. You've learned how to work with language models, how to create a prompt template, and how to get great observability into chains you create with LangSmith.\n",
     "\n",
     "This just scratches the surface of what you will want to learn to become a proficient AI Engineer. Luckily - we've got a lot of other resources!\n",
     "\n",