Fix typo in agent_structured.ipynb (#11340)

therefor -> therefore

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docs/extras/modules/agents/how_to/agent_structured.ipynb

@@ -141,11 +141,11 @@
     "When the `Response` function is called by OpenAI, we want to use that as a signal to return to the user.\n",
     "When any other function is called by OpenAI, we treat that as a tool invocation.\n",
     "\n",
-    "Therefor, our parsing logic has the following blocks:\n",
+    "Therefore, our parsing logic has the following blocks:\n",
     "\n",
-    "- If no function is called, assume that we should use the response to respond to the user, and therefor return `AgentFinish`\n",
-    "- If the `Response` function is called, respond to the user with the inputs to that function (our structured output), and therefor return `AgentFinish`\n",
-    "- If any other function is called, treat that as a tool invocation, and therefor return `AgentActionMessageLog`\n",
+    "- If no function is called, assume that we should use the response to respond to the user, and therefore return `AgentFinish`\n",
+    "- If the `Response` function is called, respond to the user with the inputs to that function (our structured output), and therefore return `AgentFinish`\n",
+    "- If any other function is called, treat that as a tool invocation, and therefore return `AgentActionMessageLog`\n",
     "\n",
     "Note that we are using `AgentActionMessageLog` rather than `AgentAction` because it lets us attach a log of messages that we can use in the future to pass back into the agent prompt."
    ]