Issue #18919: Fixed resource leaks in audio tests.

Lib/test/audiotests.py

@@ -191,13 +191,13 @@ class AudioTestsWithSourceFile(AudioTests):
                           self.sndfilenframes, self.comptype, self.compname)
 
     def test_close(self):
-        testfile = open(self.sndfilepath, 'rb')
+        with open(self.sndfilepath, 'rb') as testfile:
             f = self.f = self.module.open(testfile)
             self.assertFalse(testfile.closed)
             f.close()
             self.assertEqual(testfile.closed, self.close_fd)
-        testfile = open(TESTFN, 'wb')
-        fout = self.module.open(testfile, 'wb')
+        with open(TESTFN, 'wb') as testfile:
+            fout = self.fout = self.module.open(testfile, 'wb')
             self.assertFalse(testfile.closed)
             with self.assertRaises(self.module.Error):
                 fout.close()