Implement wl_keyboard.release

The destructor request was added in version 3. Currently, we support v7.

src/wayland/keyboard_interface.cpp

@@ -23,6 +23,11 @@ KeyboardInterfacePrivate::KeyboardInterfacePrivate(SeatInterface *s)
 {
 }
 
+void KeyboardInterfacePrivate::keyboard_release(Resource *resource)
+{
+    wl_resource_destroy(resource->handle);
+}
+
 void KeyboardInterfacePrivate::keyboard_bind_resource(Resource *resource)
 {
     const ClientConnection *focusedClient = focusedSurface ? focusedSurface->client() : nullptr;

src/wayland/keyboard_interface_p.h

@@ -63,6 +63,7 @@ public:
     QVector<quint32> pressedKeys() const;
 
 protected:
+    void keyboard_release(Resource *resource) override;
     void keyboard_bind_resource(Resource *resource) override;
 };