fix: Remove unneeded ThemeFix

Some ThemeFix no longer needed for theming with .net9.
For ListBox BorderStyle.Fixed3D does not look great in dark mode but is
rendered correctly and not overridden.

# Conflicts:
#	src/app/GitExtUtils/GitUI/Theming/ThemeFix.cs

Author: gerhardol

src/app/GitExtUtils/GitUI/Theming/ThemeFix.cs

@@ -25,14 +25,10 @@ public static void FixVisualStyle(this Control container)
                  .ForEach(SetupGroupBox);
             container.DescendantsToFix<TreeView>()
                 .ForEach(SetupTreeView);
-            container.DescendantsToFix<ListBox>()
-                .ForEach(SetupListBox);
             container.DescendantsToFix<TabControl>()
                 .ForEach(SetupTabControl);
             container.DescendantsToFix<TextBoxBase>()
                  .ForEach(SetupTextBoxBase);
-            container.DescendantsToFix<ComboBox>()
-                 .ForEach(SetupComboBox);
             container.DescendantsToFix<LinkLabel>()
                 .ForEach(SetupLinkLabel);
             container.DescendantsToFix<ToolStrip>()
@@ -71,22 +67,13 @@ private static void SetupTextBoxBase(TextBoxBase textBox)
         private static void SetupToolStrip(ToolStrip strip)
         {
             strip.UseExtendedThemeAwareRenderer();
-            strip.Items.OfType<ToolStripLabel>()
-                .ForEach(SetupToolStripLabel);
         }
 
         private static void SetupContextMenu(ContextMenuStrip strip)
         {
             strip.UseExtendedThemeAwareRenderer();
         }
 
-        private static void SetupToolStripLabel(ToolStripLabel label)
-        {
-            label.LinkColor = label.LinkColor.AdaptTextColor();
-            label.VisitedLinkColor = label.VisitedLinkColor.AdaptTextColor();
-            label.ActiveLinkColor = label.ActiveLinkColor.AdaptTextColor();
-        }
-
         private static void SetupLinkLabel(this LinkLabel label)
         {
             label.LinkColor = label.LinkColor.AdaptTextColor();
@@ -116,23 +103,6 @@ private static void SetupTabPage(TabPage page)
 
         private static void SetupTreeView(TreeView view)
         {
-            IntPtr unused = view.Handle; // force handle creation
-            view.TouchBackColor();
-            view.TouchForeColor();
-            view.LineColor = SystemColors.ControlDark;
-        }
-
-        private static void SetupListBox(ListBox view)
-        {
-            if (view.BorderStyle == BorderStyle.Fixed3D)
-            {
-                view.BorderStyle = BorderStyle.FixedSingle;
-            }
-        }
-
-        private static void SetupComboBox(this ComboBox menu)
-        {
-            menu.TouchBackColor();
         }
 
         private static void TouchBackColor(this Control c)