Remove Unused Project Includes From Files With Platform-Specific Code

A Linux include-what-you-use run cannot see the code inside _WIN32, __APPLE__ or __linux__ blocks, so its verdict is only taken where nothing the removed header declares, directly or through what it includes, is named inside those blocks. Removals also have to hold in both the Release and Debug configuration and never touch a line inside a conditional block.

src/slic3r/GUI/ThermalPreconditioningDialog.cpp

@@ -1,8 +1,6 @@
 #include "ThermalPreconditioningDialog.hpp"
 #include "I18N.hpp"
-#include "GUI.hpp"
 #include "GUI_App.hpp"
-#include "wxExtensions.hpp"
 #include "DeviceManager.hpp"
 #include "DeviceCore/DevManager.h"
 #include <wx/wx.h>
@@ -17,6 +15,8 @@
 #include <wx/font.h>
 #include <wx/event.h>
 
+class wxWindow;
+
 namespace Slic3r { namespace GUI {
 
 BEGIN_EVENT_TABLE(ThermalPreconditioningDialog, wxDialog)