effects/overview: Change default shortcut to Meta+W

Ctrl+Meta+D is already taken by the Minimize All script. "W" in Meta+W
stands for "window". Meta+O wasn't chosen because it's one of a
finger-stretcher.

BUG: 445800

src/effects/overview/kcm/overvieweffectkcm.cpp

@@ -38,7 +38,7 @@ OverviewEffectConfig::OverviewEffectConfig(QWidget *parent, const QVariantList &
     actionCollection->setConfigGroup(QStringLiteral("Overview"));
     actionCollection->setConfigGlobal(true);
 
-    const QKeySequence defaultToggleShortcut = Qt::CTRL + Qt::META + Qt::Key_D;
+    const QKeySequence defaultToggleShortcut = Qt::META + Qt::Key_W;
     QAction *toggleAction = actionCollection->addAction(QStringLiteral("Overview"));
     toggleAction->setText(i18n("Toggle Overview"));
     toggleAction->setProperty("isConfigurationAction", true);

src/effects/overview/overvieweffect.cpp

@@ -30,7 +30,7 @@ OverviewEffect::OverviewEffect()
     m_shutdownTimer->setSingleShot(true);
     connect(m_shutdownTimer, &QTimer::timeout, this, &OverviewEffect::realDeactivate);
 
-    const QKeySequence defaultToggleShortcut = Qt::CTRL + Qt::META + Qt::Key_D;
+    const QKeySequence defaultToggleShortcut = Qt::META + Qt::Key_W;
     m_toggleAction = new QAction(this);
     connect(m_toggleAction, &QAction::triggered, this, &OverviewEffect::toggle);
     m_toggleAction->setObjectName(QStringLiteral("Overview"));