docs: update agent.ipynb

persistance -> persistence

examples/langgraph-agent/agent.ipynb

@@ -9,7 +9,7 @@
     "The following example demonstrates building an agent using LangGraph. Graphiti is used to personalize agent responses based on information learned from prior conversations. Additionally, a database of products is loaded into the Graphiti graph, enabling the agent to speak to these products.\n",
     "\n",
     "The agent implements:\n",
-    "- persistance of new chat turns to Graphiti and recall of relevant Facts using the most recent message.\n",
+    "- persistence of new chat turns to Graphiti and recall of relevant Facts using the most recent message.\n",
     "- a tool for querying Graphiti for shoe information\n",
     "- an in-memory MemorySaver to maintain agent state.\n",
     "\n",