Don't skip QFileDialog retranslatability test on macOS

The test explicitly asks for a non-native file dialog, which works on
macOS as well.

Change-Id: I964c6d98501b4207c2b6c2ce1df39f654c801a43
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

tests/auto/other/languagechange/tst_languagechange.cpp

@@ -256,9 +256,6 @@ void tst_languageChange::retranslatability()
 #endif
         break;
     case FileDialog: {
-#ifdef Q_OS_MAC
-        QSKIP("The native file dialog is used on Mac OS");
-#endif
         QFileDialog dlg;
         dlg.setOption(QFileDialog::DontUseNativeDialog);
         QString tempDirPattern = QDir::tempPath();