Expose Winit's with_skip_taskbar on window creation (#12450)

# Objective

Resolves #12431.

## Solution

Added a `skip_taskbar` field to the `Window` struct (defaults to
`false`). Used in `create_windows` if the target OS is Windows.

crates/bevy_window/src/window.rs

@@ -259,6 +259,17 @@ pub struct Window {
     ///
     /// - **Android / Wayland / Web:** Unsupported.
     pub visible: bool,
+    /// Sets whether the window should be shown in the taskbar.
+    ///
+    /// If `true`, the window will not appear in the taskbar.
+    /// If `false`, the window will appear in the taskbar.
+    ///
+    /// Note that this will only take effect on window creation.
+    ///
+    /// ## Platform-specific
+    ///
+    /// - Only supported on Windows.
+    pub skip_taskbar: bool,
 }
 
 impl Default for Window {
@@ -287,6 +298,7 @@ impl Default for Window {
             canvas: None,
             window_theme: None,
             visible: true,
+            skip_taskbar: false,
         }
     }
 }

crates/bevy_winit/src/winit_windows.rs

@@ -104,6 +104,12 @@ impl WinitWindows {
             .with_transparent(window.transparent)
             .with_visible(window.visible);
 
+        #[cfg(target_os = "windows")]
+        {
+            use winit::platform::windows::WindowBuilderExtWindows;
+            winit_window_builder = winit_window_builder.with_skip_taskbar(window.skip_taskbar)
+        }
+
         #[cfg(any(
             target_os = "linux",
             target_os = "dragonfly",