### 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)

return line_edit;
}
void SpinBox::_line_edit_input(const Ref<InputEvent> &p_event) {
}
void SpinBox::_range_click_timeout() {
	if (!drag.enabled && Input::get_singleton()->is_mouse_button_pressed(MouseButton::LEFT)) {
		bool up = get_local_mouse_position().y < (get_size().height / 2);
		double step = get_custom_arrow_step() != 0.0 ? get_custom_arrow_step() : get_step();
		set_value(get_value() + (up ? step : -step));
		if (range_click_timer->is_one_shot()) {
			range_click_timer->set_wait_time(0.075);
			range_click_timer->set_one_shot(false);
			range_click_timer->start();
		}
	} else {
		range_click_timer->stop();
	}
}
void SpinBox::_release_mouse() {
	if (drag.enabled) {
		drag.enabled = false;
		Input::get_singleton()->set_mouse_mode(Input::MOUSE_MODE_HIDDEN);
		warp_mouse(drag.capture_pos);
		Input::get_singleton()->set_mouse_mode(Input::MOUSE_MODE_VISIBLE);
	}
}
void SpinBox::gui_input(const Ref<InputEvent> &p_event) {