### 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)

panel->set_theme_type_variation(SNAME("TooltipPanel"));
	
	
	Control *base_tooltip = tooltip_owner->make_custom_tooltip(tooltip_text);
	
	if (!base_tooltip) {
		gui.tooltip_label = memnew(Label);
		gui.tooltip_label->set_theme_type_variation(SNAME("TooltipLabel"));
		gui.tooltip_label->set_auto_translate(gui.tooltip_control->is_auto_translating());
		gui.tooltip_label->set_text(tooltip_text);
		base_tooltip = gui.tooltip_label;
		panel->connect("mouse_entered", callable_mp(this, &Viewport::_gui_cancel_tooltip));
	}
	base_tooltip->set_anchors_and_offsets_preset(Control::PRESET_FULL_RECT);
	panel->set_transient(true);
	panel->set_flag(Window::FLAG_NO_FOCUS, true);
	panel->set_flag(Window::FLAG_POPUP, false);
	panel->set_flag(Window::FLAG_MOUSE_PASSTHROUGH, true);
	panel->set_wrap_controls(true);
	panel->add_child(base_tooltip);
	panel->gui_parent = this;
	gui.tooltip_popup = panel;
	tooltip_owner->add_child(gui.tooltip_popup);
	Point2 tooltip_offset = GLOBAL_GET("display/mouse_cursor/tooltip_position_offset");
	Rect2 r(gui.tooltip_pos + tooltip_offset, gui.tooltip_popup->get_contents_minimum_size());
	r.size = r.size.min(panel->get_max_size());
	Window *window = gui.tooltip_popup->get_parent_visible_window();
	Rect2i vr;
	if (gui.tooltip_popup->is_embedded()) {
		vr = gui.tooltip_popup->get_embedder()->get_visible_rect();