### 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)

is_mouse = true;
			physics_has_last_mousepos = true;
			physics_last_mousepos = pos;
			physics_last_mouse_state.alt = mb->is_alt_pressed();
			physics_last_mouse_state.shift = mb->is_shift_pressed();
			physics_last_mouse_state.control = mb->is_ctrl_pressed();
			physics_last_mouse_state.meta = mb->is_meta_pressed();
			if (mb->is_pressed()) {
				physics_last_mouse_state.mouse_mask.set_flag(mouse_button_to_mask(mb->get_button_index()));
			} else {
				physics_last_mouse_state.mouse_mask.clear_flag(mouse_button_to_mask(mb->get_button_index()));
				
				if (mb->get_device() == InputEvent::DEVICE_ID_EMULATION) {
					physics_has_last_mousepos = false;
				}
			}
		}
		Ref<InputEventKey> k = ev;
		if (k.is_valid()) {
			
			physics_last_mouse_state.alt = k->is_alt_pressed();
			physics_last_mouse_state.shift = k->is_shift_pressed();
			physics_last_mouse_state.control = k->is_ctrl_pressed();
			physics_last_mouse_state.meta = k->is_meta_pressed();
			continue;
		}
		Ref<InputEventScreenDrag> sd = ev;
		if (sd.is_valid()) {
			pos = sd->get_position();
		}