Don't rely on implicit conversion from int to QUuid

Not available in Qt6 anymore.

src/effects/screenshot/screenshotdbusinterface2.cpp

@@ -334,7 +334,7 @@ QVariantMap ScreenShotDBusInterface2::CaptureWindow(const QString &handle,
         return QVariantMap();
     }
 
-    EffectWindow *window = effects->findWindow(handle);
+    EffectWindow *window = effects->findWindow(QUuid(handle));
     if (!window) {
         bool ok;
         const int winId = handle.toInt(&ok);

src/kcmkwin/kwinrules/kcmrules.cpp

@@ -72,7 +72,7 @@ void KCMKWinRules::parseArguments(const QStringList &args)
             uuid = QUuid(arg);
             nextArgIsUuid = false;
         } else if (arg.startsWith("uuid=")) {
-            uuid = arg.mid(strlen("uuid="));
+            uuid = QUuid(arg.mid(strlen("uuid=")));
         } else if (arg == QLatin1String("whole-app")) {
             m_wholeApp = true;
         }

src/plugins/screencast/screencastmanager.cpp

@@ -84,7 +84,7 @@ private:
 
 void ScreencastManager::streamWindow(KWaylandServer::ScreencastStreamV1Interface *waylandStream, const QString &winid)
 {
-    auto *toplevel = Workspace::self()->findToplevel(winid);
+    auto *toplevel = Workspace::self()->findToplevel(QUuid(winid));
 
     if (!toplevel) {
         waylandStream->sendFailed(i18n("Could not find window id %1", winid));