Implement ToolStripSystemDarkModeRenderer.

Author: KlausLoeffelmann

src/System.Windows.Forms/System/Windows/Forms/Controls/ToolStrips/ToolStripManager.cs

@@ -546,24 +546,12 @@ public static bool VisualStylesEnabled
 
     internal static ToolStripRenderer CreateRenderer(ToolStripManagerRenderMode renderMode)
     {
-        switch (renderMode)
+        return renderMode switch
         {
-            case ToolStripManagerRenderMode.System:
-                return new ToolStripSystemRenderer(isDefault: true);
-            case ToolStripManagerRenderMode.Professional:
-#pragma warning disable WFO5001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
-                if (Application.IsDarkModeEnabled)
-                {
-                    return new ToolStripProfessionalRenderer(new DarkProfessionalColors());
-                }
-#pragma warning restore WFO5001
-
-                return new ToolStripProfessionalRenderer(isDefault: true);
-
-            case ToolStripManagerRenderMode.Custom:
-            default:
-                return new ToolStripSystemRenderer(isDefault: true);
-        }
+            ToolStripManagerRenderMode.System => new ToolStripSystemRenderer(isDefault: true),
+            ToolStripManagerRenderMode.Professional => new ToolStripProfessionalRenderer(isDefault: true),
+            _ => new ToolStripSystemRenderer(isDefault: true),
+        };
     }
 
     internal static ToolStripRenderer CreateRenderer(ToolStripRenderMode renderMode)