### 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)

mm->set_global_position(physics_last_mousepos);
			mm->set_position(physics_last_mousepos);
			mm->set_alt_pressed(physics_last_mouse_state.alt);
			mm->set_shift_pressed(physics_last_mouse_state.shift);
			mm->set_ctrl_pressed(physics_last_mouse_state.control);
			mm->set_meta_pressed(physics_last_mouse_state.meta);
			mm->set_button_mask(physics_last_mouse_state.mouse_mask);
			physics_picking_events.push_back(mm);
		}
	}
	while (physics_picking_events.size()) {
		Ref<InputEvent> ev = physics_picking_events.front()->get();
		physics_picking_events.pop_front();
		Vector2 pos;
		bool is_mouse = false;
		Ref<InputEventMouseMotion> mm = ev;
		if (mm.is_valid()) {
			pos = mm->get_position();
			is_mouse = true;
			physics_has_last_mousepos = true;
			physics_last_mousepos = pos;
			physics_last_mouse_state.alt = mm->is_alt_pressed();
			physics_last_mouse_state.shift = mm->is_shift_pressed();
			physics_last_mouse_state.control = mm->is_ctrl_pressed();
			physics_last_mouse_state.meta = mm->is_meta_pressed();
			physics_last_mouse_state.mouse_mask = mm->get_button_mask();
		}
		Ref<InputEventMouseButton> mb = ev;
		if (mb.is_valid()) {
			pos = mb->get_position();