### Godot version

4.0.3.stable

### System information

Windows 10/11

### Issue description

I want the player's cursor to change when highlighting pickable Area2Ds; to do this, I have the areas modify the `mouse_default_cursor_shape` property on an external Control when the mouse enters or exits. If another Control appears in front of the Area2D while the mouse is over it, there is a chance that the project will crash.

Nothing prints to the IDE's output on this crash. If running the editor with console, then
```
ERROR: Condition "slot >= slot_max" is true. Returning: nullptr
   at: get_instance (./core/object/object.h:972)
```
will sometimes appear alongside the crash. If it appears, it always appears twice.

When I run a debug build of the editor through WinDbg, WinDbg will catch the following exception:
```
(3b58.2aac): Access violation - code c0000005 (!!! second chance !!!)
godot_windows_editor_x86_64!ObjectDB::get_instance [inlined in godot_windows_editor_x86_64!Viewport::_cleanup_mouseover_colliders+0x6f]:
00007ff6`ac254a1f 488b5310        mov     rdx,qword ptr [rbx+10h] ds:cccccccc`c31c419b=????????????????
```
When using this method, the exception is not random; it always occurs on the first attempt.

### Steps to reproduce

- Open the minimal reproduction project in the editor.
- Run the project.
- Click on the Area2D (you'll want visible collision shapes on).
- A full-screen button will pop up. If the game does not crash at this point, clicking the button will hide it so you can try again. It should crash within a few seconds of mashing.

### Minimal reproduction project

[Crash Test.zip](https://github.com/godotengine/godot/files/12027772/Crash.Test.zip)

ERR_READ_THREAD_GUARD_V(false);
	return own_world_3d.is_valid();
}
void Viewport::_propagate_enter_world_3d(Node *p_node) {
	if (p_node != this) {
		if (!p_node->is_inside_tree()) { 
			return;
		}
		if (Object::cast_to<Node3D>(p_node) || Object::cast_to<WorldEnvironment>(p_node)) {
			p_node->notification(Node3D::NOTIFICATION_ENTER_WORLD);
		} else {
			Viewport *v = Object::cast_to<Viewport>(p_node);
			if (v) {
				if (v->world_3d.is_valid() || v->own_world_3d.is_valid()) {
					return;
				}
			}
		}
	}
	for (int i = 0; i < p_node->get_child_count(); i++) {
		_propagate_enter_world_3d(p_node->get_child(i));
	}
}
void Viewport::_propagate_exit_world_3d(Node *p_node) {