Remove 4 era migration code and legacy plugin loading for Qt6

kcms/kded/modulesmodel.cpp

@@ -152,6 +152,7 @@ static QVector<KPluginMetaData> availableModules()
     for (const KPluginMetaData &md : qAsConst(plugins)) {
         moduleIds.insert(md.pluginId());
     }
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     // also search for old .desktop based kded modules
     const KPluginInfo::List oldStylePlugins = KPluginInfo::fromServices(KServiceTypeTrader::self()->query(QStringLiteral("KDEDModule")));
     for (const KPluginInfo &info : oldStylePlugins) {
@@ -166,6 +167,7 @@ static QVector<KPluginMetaData> availableModules()
             plugins.append(info.toMetaData());
         }
     }
+#endif
     return plugins;
 }
 

kcms/mouse/backends/x11/evdev_settings.cpp

@@ -11,7 +11,9 @@
 #include <QDBusConnection>
 #include <QDBusMessage>
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 #include "../migrationlib/kdelibs4config.h"
+#endif
 
 void EvdevSettings::apply(X11EvdevBackend *backend, bool force)
 {
@@ -130,8 +132,10 @@ void EvdevSettings::save()
     group.sync();
     kcminputProfile->sync();
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     Kdelibs4SharedConfig::syncConfigGroup(QLatin1String("Mouse"), "kcminputrc");
     Kdelibs4SharedConfig::syncConfigGroup(QLatin1String("KDE"), "kdeglobals");
+#endif
 
     emitChange(SettingsChanged, SETTINGS_MOUSE);
 }

kcms/mouse/kcm/xlib/xlib_config.cpp

@@ -16,8 +16,6 @@
 #include "../configcontainer.h"
 #include "backends/x11/x11_evdev_backend.h"
 
-#include "../../../migrationlib/kdelibs4config.h"
-
 #include <KLocalizedString>
 #include <KToolInvocation>
 //#include <KConfig>