fix(OpenAI Node): Simplify code (#5618)

fix(OpenAI Node): Simplifiy code

packages/nodes-base/nodes/OpenAi/ChatDescription.ts

@@ -1,5 +1,4 @@
 import type { INodeExecutionData, INodeProperties } from 'n8n-workflow';
-import { chatBodyPresend } from './ChatFunctions';
 
 export const chatOperations: INodeProperties[] = [
 	{
@@ -115,7 +114,7 @@ const completeOperations: INodeProperties[] = [
 			send: {
 				type: 'body',
 				property: 'messages',
-				preSend: [chatBodyPresend],
+				value: '={{ $value.messages }}',
 			},
 		},
 	},

packages/nodes-base/nodes/OpenAi/ChatFunctions.ts

@@ -1,14 +0,0 @@
-import type { IDataObject, IExecuteSingleFunctions, IHttpRequestOptions } from 'n8n-workflow';
-
-export async function chatBodyPresend(
-	this: IExecuteSingleFunctions,
-	requestOptions: IHttpRequestOptions,
-): Promise<IHttpRequestOptions> {
-	const prompts = this.getNodeParameter('prompt', '{}') as IDataObject;
-
-	requestOptions.body = Object.assign({}, requestOptions.body, {
-		messages: prompts.messages,
-	});
-
-	return requestOptions;
-}