Qt: Remove unused function

Author: stenzek

src/duckstation-qt/mainwindow.cpp

@@ -1576,11 +1576,6 @@ void MainWindow::onGitHubRepositoryActionTriggered()
   QtUtils::OpenURL(this, "https://github.com/stenzek/duckstation/");
 }
 
-void MainWindow::onIssueTrackerActionTriggered()
-{
-  QtUtils::OpenURL(this, "https://www.duckstation.org/issues.html");
-}
-
 void MainWindow::onDiscordServerActionTriggered()
 {
   QtUtils::OpenURL(this, "https://www.duckstation.org/discord.html");

src/duckstation-qt/mainwindow.h

@@ -293,7 +293,6 @@ class MainWindow final : public QMainWindow
   void onViewSortByActionTriggered();
   void onViewSortOrderActionTriggered();
   void onGitHubRepositoryActionTriggered();
-  void onIssueTrackerActionTriggered();
   void onDiscordServerActionTriggered();
   void onAboutActionTriggered();
   void onCheckForUpdatesActionTriggered();

src/duckstation-qt/resources/duckstation-qt.qrc

@@ -7,7 +7,6 @@
 		<file>controllers/justifier.svg</file>
 		<file>controllers/mouse.svg</file>
 		<file>controllers/negcon.svg</file>
-		<file>icons/IssueTracker.png</file>
 		<file>icons/QT.png</file>
 		<file>icons/UpdateDuck.png</file>
 		<file>icons/address-book-new-22.png</file>