Fix tst_qicns test for INTEGRITY

- There is no possibility to use file system on our INTEGRITY test device.
  Add test sciping

Task-number: QTBUG-99123
Pick-to: 6.2 6.3
Change-Id: Icb84eb73b6010d4aa4ca19a4d3a0ecaa02216a6f
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

tests/auto/icns/tst_qicns.cpp

@@ -100,6 +100,9 @@ void tst_qicns::writeIcons_data()
 
 void tst_qicns::writeIcons()
 {
+#ifdef Q_OS_INTEGRITY
+    QSKIP("Unable to create temp dir on INTEGRITY device.");
+#endif
     QTemporaryDir temp(QDir::tempPath() + QStringLiteral("/tst_qincs"));
     QVERIFY2(temp.isValid(), "Unable to create temp dir.");