gpui: Fix invalid unwrap in windows window creation (#42426)

Fixes ZED-34M

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/gpui/src/platform/windows/window.rs

@@ -453,8 +453,9 @@ impl WindowsWindow {
 
         // Failure to create a `WindowsWindowState` can cause window creation to fail,
         // so check the inner result first.
-        let this = context.inner.take().unwrap()?;
+        let this = context.inner.take().transpose()?;
         let hwnd = creation_result?;
+        let this = this.unwrap();
 
         register_drag_drop(&this)?;
         configure_dwm_dark_mode(hwnd, appearance);