### 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)

if (gui.mouse_over) {
		_gui_call_notification(gui.mouse_over, Control::NOTIFICATION_MOUSE_EXIT);
		gui.mouse_over = nullptr;
	}
}
void Viewport::_drop_mouse_focus() {
	Control *c = gui.mouse_focus;
	BitField<MouseButtonMask> mask = gui.mouse_focus_mask;
	gui.mouse_focus = nullptr;
	gui.forced_mouse_focus = false;
	gui.mouse_focus_mask.clear();
	for (int i = 0; i < 3; i++) {
		if ((int)mask & (1 << i)) {
			Ref<InputEventMouseButton> mb;
			mb.instantiate();
			mb->set_position(c->get_local_mouse_position());
			mb->set_global_position(c->get_local_mouse_position());
			mb->set_button_index(MouseButton(i + 1));
			mb->set_pressed(false);
			mb->set_device(InputEvent::DEVICE_ID_INTERNAL);
			c->_call_gui_input(mb);
		}
	}
}
void Viewport::_drop_physics_mouseover(bool p_paused_only) {