Fix compilation with -feature-wayland_text_input_v4_wip

Someone changed something so this is no longer implicitly
included, so we need to add it explicitly.

Pick-to: 6.5 6.6
Change-Id: Ie4b5c5194e32d4b192444c931da56b7ec9009cd2
Reviewed-by: David Edmundson <davidedmundson@kde.org>

src/plugins/platforms/wayland/qwaylandtextinputv4_p.h

@@ -18,6 +18,7 @@
 #include "qwaylandtextinputinterface_p.h"
 #include <QtWaylandClient/private/qwayland-text-input-unstable-v4-wip.h>
 #include <qwaylandinputmethodeventbuilder_p.h>
+#include <QLoggingCategory>
 
 struct wl_callback;
 struct wl_callback_listener;