typo in locall llms fixed (#9755)

Hi, 

I noticed a typo in the local_llms.ipynb file and fixed it. The word
challenge is without 'a' in the original file.
@baskaryan , @eyurtsev

Thanks.

Co-authored-by: Fliprise <fliprise@Fliprises-MacBook-Pro.local>

docs/extras/guides/local_llms.ipynb

@@ -146,7 +146,7 @@
    "source": [
     "## Environment\n",
     "\n",
-    "Inference speed is a chllenge when running models locally (see above).\n",
+    "Inference speed is a challenge when running models locally (see above).\n",
     "\n",
     "To minimize latency, it is desiable to run models locally on GPU, which ships with many consumer laptops [e.g., Apple devices](https://www.apple.com/newsroom/2022/06/apple-unveils-m2-with-breakthrough-performance-and-capabilities/).\n",
     "\n",