egui-winit: re-enable window transparency (#1126)

`winit` 0.26.1 fixes the crash on Windows 11

egui_demo_app/src/main.rs

@@ -10,7 +10,7 @@ fn main() {
     let app = egui_demo_lib::WrapApp::default();
     let options = eframe::NativeOptions {
         // Let's show off that we support transparent windows
-        // transparent: true,
+        transparent: true,
         drag_and_drop_support: true,
         ..Default::default()
     };