test: mock nodemailer network calls (#9957)

In tests, nodemailer was making network calls to create test accounts
using ethereal.email. This mocks them appropriately.

test/jest.setup.js

@@ -1,6 +1,8 @@
 import console from 'console'
 global.console = console
 
+import nodemailer from 'nodemailer'
+
 import { generateDatabaseAdapter } from './generateDatabaseAdapter.js'
 
 process.env.PAYLOAD_DISABLE_ADMIN = 'true'
@@ -11,6 +13,18 @@ process.env.PAYLOAD_PUBLIC_CLOUD_STORAGE_ADAPTER = 's3'
 process.env.NODE_OPTIONS = '--no-deprecation'
 process.env.PAYLOAD_CI_DEPENDENCY_CHECKER = 'true'
 
+// Mock createTestAccount to prevent calling external services
+jest.spyOn(nodemailer, 'createTestAccount').mockImplementation(() => {
+  return Promise.resolve({
+    imap: { host: 'imap.test.com', port: 993, secure: true },
+    pass: 'testpass',
+    pop3: { host: 'pop3.test.com', port: 995, secure: true },
+    smtp: { host: 'smtp.test.com', port: 587, secure: false },
+    user: 'testuser',
+    web: 'https://webmail.test.com',
+  })
+})
+
 const dbAdapter = process.env.PAYLOAD_DATABASE || 'mongodb'
 
 generateDatabaseAdapter(dbAdapter)