Godot crashes when minimizing a subwindow

### Tested versions

Reproducible in 4.3-dev3, dev4, and dev5

### System information

Godot v4.3.dev4 - Windows 10.0.19045 - GLES3 (Compatibility) - Intel(R) HD Graphics 4600 (Intel Corporation; 20.19.15.5126) - Intel(R) Core(TM) i3-4330 CPU @ 3.50GHz (4 Threads)

### Issue description

Basically I opened the script editor in a subwindow, tried to minimize it, and Godot crashed. Later on I checked if this also happens in normal projects and yes, it does.

**Here's a short video:**

https://github.com/godotengine/godot/assets/136469511/f790186c-0758-4514-8296-9c9d8843bbea

### Steps to reproduce

1. Add a **Window** node to your scene.
2. Make sure to disable this setting **display/window/subwindows/embed_subwindows**.
3. Minimize it.

-- Or within Godot --
1. Go to script editor.
2. Make it floating.
5. Minimize it.

### Minimal reproduction project (MRP)

N/A.

Start by reproducing the crash with a Window node while display/window/subwindows/embed_subwindows is disabled, then compare it with a floating script editor subwindow on Windows. Trace the subwindow minimize path from these entry points; done means minimizing either kind of subwindow no longer crashes Godot.

Written by the indexing model from the issue text.