### Godot version

4.1.dev 2e273f0e35800f2bcc7c05db54100caa97928f69

### System information

macOS 13.4

### Issue description

Removing a SpinBox from the node tree using `remove_child` during the line edit text submit signal will crash the engine.

```
handle_crash: Program crashed with signal 11
Engine version: Godot Engine v4.1.dev.custom_build (2e273f0e35800f2bcc7c05db54100caa97928f69)
Dumping the backtrace. Please include this when reporting the bug to the project developer.
[1] 1   libsystem_platform.dylib            0x0000000183b5aa24 _sigtramp + 56
[2] Viewport::gui_get_focus_owner() (in godot.macos.editor.arm64) + 32
[3] SpinBox::_line_edit_focus_exit() (in godot.macos.editor.arm64) + 28
[4] CallQueue::_call_function(Callable const&, Variant const*, int, bool) (in godot.macos.editor.arm64) + 336
[5] CallQueue::flush() (in godot.macos.editor.arm64) + 908
[6] SceneTree::physics_process(double) (in godot.macos.editor.arm64) + 244
[7] Main::iteration() (in godot.macos.editor.arm64) + 528
```

### Steps to reproduce

Open the minimal reproduction project, click on the SpinBox, press enter, and the engine crashes.

### Minimal reproduction project

[SpinBoxTextSubmitCrash.zip](https://github.com/godotengine/godot/files/11631081/SpinBoxTextSubmitCrash.zip)

ERR_READ_THREAD_GUARD_V(SDF_SCALE_100_PERCENT);
	return sdf_scale;
}
Transform2D Viewport::get_screen_transform() const {
	ERR_READ_THREAD_GUARD_V(Transform2D());
	return get_screen_transform_internal();
}
Transform2D Viewport::get_screen_transform_internal(bool p_absolute_position) const {
	ERR_READ_THREAD_GUARD_V(Transform2D());
	return get_final_transform();
}
void Viewport::update_mouse_cursor_state() {
	
	Window *base_window = get_base_window();
	if (base_window) {
		base_window->update_mouse_cursor_state();
	}
}
void Viewport::set_canvas_cull_mask(uint32_t p_canvas_cull_mask) {
	ERR_MAIN_THREAD_GUARD;
	canvas_cull_mask = p_canvas_cull_mask;
	RenderingServer::get_singleton()->viewport_set_canvas_cull_mask(viewport, canvas_cull_mask);
}
uint32_t Viewport::get_canvas_cull_mask() const {
	ERR_READ_THREAD_GUARD_V(0);
	return canvas_cull_mask;
}
void Viewport::set_canvas_cull_mask_bit(uint32_t p_layer, bool p_enable) {