[plugins/windowsystem] Fix compilation with no-deprecated build of KWindowSystem

Summary:
This change ensures that KWin can be built with a version of KWS that
doesn't have any deprecated stuff. I assume that no distro ships such
builds of KWS and it's only a developer thing.

I didn't backport KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE macro because
the next release of Plasma (5.18) depends on KF 5.66.

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D26642

plugins/windowsystem/windoweffects.cpp

@@ -144,9 +144,11 @@ void WindowEffects::enableBackgroundContrast(WId window, bool enable, qreal cont
     }
 }
 
+#if KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE(5, 67)
 void WindowEffects::markAsDashboard(WId window)
 {
     Q_UNUSED(window)
 }
+#endif
 
 }

plugins/windowsystem/windoweffects.h

@@ -41,7 +41,9 @@ public:
     void highlightWindows(WId controller, const QList<WId> &ids) override;
     void enableBlurBehind(WId window, bool enable = true, const QRegion &region = QRegion()) override;
     void enableBackgroundContrast(WId window, bool enable = true, qreal contrast = 1, qreal intensity = 1, qreal saturation = 1, const QRegion &region = QRegion()) override;
+#if KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE(5, 67)
     void markAsDashboard(WId window) override;
+#endif
 };
 
 }