[Update] Default LLM (#3587)

docs/open-source/features/openai_compatibility.mdx

@@ -27,7 +27,7 @@ messages = [
 user_id = "alice"
 chat_completion = client.chat.completions.create(
     messages=messages,
-    model="gpt-4o-mini",
+    model="gpt-4.1-nano-2025-04-14",
     user_id=user_id
 )
 # Memory saved after this will look like: "Loves Indian food. Allergic to cheese and cannot eat pizza."
@@ -42,7 +42,7 @@ messages = [
 
 chat_completion = client.chat.completions.create(
     messages=messages,
-    model="gpt-4o-mini",
+    model="gpt-4.1-nano-2025-04-14",
     user_id=user_id
 )
 print(chat_completion.choices[0].message.content)
@@ -73,7 +73,7 @@ chat_completion = client.chat.completions.create(
             "content": "What's the capital of France?",
         }
     ],
-    model="gpt-4o",
+    model="gpt-4.1-nano-2025-04-14",
 )
 ```