Cancel interactive move resize only on Wayland

On X11, kwin receives spurious output change events non stop when an
override redirect window is moved around. They stop after restarting
kwin and resume after the output layout changes. It's unclear what the
source of the issue is, but it's likely Xorg.

src/workspace.cpp

@@ -1225,8 +1225,11 @@ void Workspace::updateOutputs(const std::optional<QList<Output *>> &outputOrder)
     const auto availableOutputs = kwinApp()->outputBackend()->outputs();
     const auto oldOutputs = m_outputs;
 
-    if (m_moveResizeWindow) {
-        m_moveResizeWindow->cancelInteractiveMoveResize();
+    // On X11, we receive spurious output change events when windows move around.
+    if (waylandServer()) {
+        if (m_moveResizeWindow) {
+            m_moveResizeWindow->cancelInteractiveMoveResize();
+        }
     }
 
     m_outputs.clear();