Fix keyboard layout tests

Don't give the InputConfig a separate config instance. I've seen it
being changed after having initialized the xkb instance which would
break the shared instance.
Using a simple config rather than reading the configuration from
the actual code-path shouldn't make a difference as a test it will be
using ~/.qttest which should be cleaned upp

autotests/integration/keyboard_layout_test.cpp

@@ -82,7 +82,6 @@ void KeyboardLayoutTest::initTestCase()
 
     kwinApp()->setConfig(KSharedConfig::openConfig(QString(), KConfig::SimpleConfig));
     kwinApp()->setKxkbConfig(KSharedConfig::openConfig(QString(), KConfig::SimpleConfig));
-    InputConfig::self()->setInputConfig(KSharedConfig::openConfig(QString(), KConfig::SimpleConfig));
 
     kwinApp()->start();
     QVERIFY(workspaceCreatedSpy.wait());