Remove 'openai/gpt-5.4' model from OpenAIModels type

Removed 'openai/gpt-5.4' from the list of OpenAI models.

Author: Topherhindman

agents/src/inference/llm.ts

@@ -17,7 +17,6 @@ import { type AnyString, createAccessToken } from './utils.js';
 const DEFAULT_BASE_URL = 'https://agent-gateway.livekit.cloud/v1';
 
 export type OpenAIModels =
-  | 'openai/gpt-5.4'
   | 'openai/gpt-5.2'
   | 'openai/gpt-5.2-chat-latest'
   | 'openai/gpt-5.1'