docs: Update function "run" to "invoke" (langchain-ai#18499)

Currently llm_checker.ipynb uses a function "run".
Update to "invoke" to avoid following warning.

LangChainDeprecationWarning: The function `run` was deprecated in
LangChain 0.1.0
and will be removed in 0.2.0. Use invoke instead.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>

cookbook/llm_checker.ipynb

@@ -50,7 +50,7 @@
     "\n",
     "checker_chain = LLMCheckerChain.from_llm(llm, verbose=True)\n",
     "\n",
-    "checker_chain.run(text)"
+    "checker_chain.invoke(text)"
    ]
   },
   {