Remove orphaned function implementing close button that was removed

qrenderdoc/Windows/Dialogs/CaptureDialog.cpp

@@ -878,11 +878,6 @@ void CaptureDialog::on_launch_clicked()
   TriggerCapture();
 }
 
-void CaptureDialog::on_close_clicked()
-{
-  ToolWindowManager::closeToolWindow(this);
-}
-
 void CaptureDialog::on_processList_activated(const QModelIndex &index)
 {
   TriggerCapture();

qrenderdoc/Windows/Dialogs/CaptureDialog.h

@@ -95,7 +95,6 @@ private slots:
   void on_loadLastCapture_clicked();
 
   void on_launch_clicked();
-  void on_close_clicked();
 
   void on_toggleGlobal_clicked();