Remove leftover source file

I was initially going to put implementation in a separate CPP file but due to DialogResultRender
being a class template the implementation details need to be part of the header.

Signed-off-by: Mavridis Philippe <mavridisf@gmail.com>

src/dialog_result_sender.cpp

@@ -1,39 +0,0 @@
-/*******************************************************************************
-  XDG desktop portal implementation for TDE
-  Copyright © 2024 Mavridis Philippe <mavridisf@gmail.com>
-
-  This program or library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public License as
-  published by the Free Software Foundation; either version 2.1 of the License,
-  or (at your option) any later version.
-
-  This library is distributed in the hope that it will be useful, but WITHOUT
-  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-  FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
-  details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with this library; if not, write to the Free Software Foundation, Inc.,
-  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
-
-  Improvements and feedback are welcome!
-*******************************************************************************/
-
-// Portal
-#include "dialog_result_sender.h"
-
-template <class T>
-DialogResultSender<T>::DialogResultSender(T* portal, int asyncCallId, TQDialog *dlg,
-                                          ResultPrepareCallback<T> prepareCb, ResultSendCallback<T> sendCb)
-{}
-
-template <class T>
-DialogResultSender<T>::~DialogResultSender()
-{
-}
-
-template <class T>
-void DialogResultSender<T>::run()
-{
-
-}