Mark known test failures in Windows developer build.

Previously, the CI system has not been testing on Windows with the
-developer-build configure flag. Mark known failures for this
configuration so that tests can be run in enforcing mode.

Change-Id: I5fbbbe09a7b400d626107c66dcbd5c5469a45b20
Reviewed-by: Sergio Ahumada <sergio.ahumada@nokia.com>

tests/auto/corelib/io/qsettings/tst_qsettings.cpp

@@ -1989,6 +1989,9 @@ void tst_QSettings::setIniCodec()
 
     QConfFile::clearCache();
 
+#ifdef Q_OS_WIN
+    QEXPECT_FAIL("", "QTBUG-25446", Abort);
+#endif
     QCOMPARE(actualContents4, expeContents4);
     QCOMPARE(actualContents5, expeContents5);