Dirty fix for App hanging when windows are invisible on WindowsOS (#1…

…4155)

# Objective

- Fixes #14135 

## Solution

- If no windows are visible, app updates will run regardless of redraw
call result.

This a relatively dirty fix, a more robust solution is desired in the
long run:
#1343 (comment)

https://discord.com/channels/691052431525675048/1253771396832821270/1258805997011730472
The solution would disconnect rendering from app updates.

## Testing

- `window_settings` now works

## Other platforms

Not a problem on Linux:
https://discord.com/channels/691052431525675048/692572690833473578/1259526650622640160
Not a problem on MacOS:
https://discord.com/channels/691052431525675048/692572690833473578/1259563986148659272

crates/bevy_winit/src/state.rs

@@ -504,8 +504,16 @@ impl<T: Event> ApplicationHandler<T> for WinitAppRunnerState<T> {
         let begin_frame_time = Instant::now();
 
         if should_update {
+            let (_, windows) = focused_windows_state.get(self.world());
+            // If no windows exist, this will evaluate to `true`.
+            let all_invisible = windows.iter().all(|w| !w.1.visible);
+
             // Not redrawing, but the timeout elapsed.
-            if !self.ran_update_since_last_redraw {
+            //
+            // Additional condition for Windows OS.
+            // If no windows are visible, redraw calls will never succeed, which results in no app update calls being performed.
+            // This is a temporary solution, full solution is mentioned here: https://github.com/bevyengine/bevy/issues/1343#issuecomment-770091684
+            if !self.ran_update_since_last_redraw || all_invisible {
                 self.run_app_update();
                 self.ran_update_since_last_redraw = true;
             } else {