[UI] Remove DolphinQt

Source/Core/DolphinQt/AboutDialog.h

@@ -1,26 +0,0 @@
-// Copyright 2014 Dolphin Emulator Project
-// Licensed under GPLv2+
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <memory>
-#include <QDialog>
-
-// Predefinitions
-namespace Ui
-{
-class DAboutDialog;
-}
-
-class DAboutDialog final : public QDialog
-{
-	Q_OBJECT
-
-public:
-	explicit DAboutDialog(QWidget* parent_widget = nullptr);
-	~DAboutDialog();
-
-private:
-	std::unique_ptr<Ui::DAboutDialog> m_ui;
-};