chore(internal): fix tests failing on node v18

Author: RobertCraigie

tests/lib/azure.test.ts

@@ -1,6 +1,7 @@
 import { AzureOpenAI } from 'openai';
 import { APIUserAbortError } from 'openai';
 import { type Response, RequestInit, RequestInfo } from 'openai/internal/builtin-types';
+import { File } from 'node:buffer';
 
 const defaultFetch = fetch;
 

tests/uploads.test.ts

@@ -1,6 +1,7 @@
 import fs from 'fs';
 import type { ResponseLike } from 'openai/internal/to-file';
 import { toFile } from 'openai/uploads';
+import { File } from 'node:buffer';
 
 class MyClass {
   name: string = 'foo';