bpo-40275: Use new test.support helper submodules in tests (GH-21772)

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index be11337..119da12 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -25,7 +25,7 @@
 import unittest
 import sqlite3 as sqlite
 
-from test.support import TESTFN, unlink
+from test.support.os_helper import TESTFN, unlink
 
 
 class ModuleTests(unittest.TestCase):