win32: drop application handler on `WM_ENDSESSION`

[Legend-Master]

• [x] Tested on all platforms changed
• [x] Added an entry to the changelog module if knowledge of this change could be valuable to users
• [ ] Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• [ ] Created or updated an example program if it would help users understand this functionality

Reference tao PR: https://github.com/tauri-apps/tao/pull/1126 Implemented the solution talked in https://github.com/rust-windowing/winit/pull/4149#issuecomment-3570658134