update docs

Co-authored-by: Douwe Maan <[email protected]>

Author: GDaamn

docs/models/openai.md

@@ -174,7 +174,7 @@ When the `openai_previous_response_id` field is set to `'auto'`, Pydantic AI wil
 from pydantic_ai import Agent
 from pydantic_ai.models.openai import OpenAIResponsesModel, OpenAIResponsesModelSettings
 
-model = OpenAIResponsesModel('gpt-4o')
+model = OpenAIResponsesModel('gpt-5')
 agent = Agent(model=model)
 
 result1 = agent.run_sync('Tell me a joke.')