wayland: Set default cursor shape for the root window

Previously, it was done by plasmashell, now it needs to be done by kwin.

BUG: 442539

src/xwl/xwayland.cpp

@@ -9,6 +9,7 @@
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "xwayland.h"
+#include "cursor.h"
 #include "databridge.h"
 #include "dnd.h"
 #include "xwldrophandler.h"
@@ -385,6 +386,11 @@ void Xwayland::handleXwaylandReady()
             this, &Xwayland::handleSelectionFailedToClaimOwnership);
     m_selectionOwner->claim(true);
 
+    Cursor *mouseCursor = Cursors::self()->mouse();
+    if (mouseCursor) {
+        Xcb::defineCursor(kwinApp()->x11RootWindow(), mouseCursor->x11Cursor(Qt::ArrowCursor));
+    }
+
     DataBridge::create(this);
 
     auto env = m_app->processStartupEnvironment();