### 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)

Ref<Expression> expr;
	expr.instantiate();
	String num = TS->parse_number(p_string);
	
	Error err = expr->parse(num.trim_prefix(prefix + " ").trim_suffix(" " + suffix));
	if (err != OK) {
		return;
	}
	Variant value = expr->execute(Array(), nullptr, false, true);
	if (value.get_type() != Variant::NIL) {
		set_value(value);
	}
	_update_text();
}
void SpinBox::_text_changed(const String &p_string) {
	int cursor_pos = line_edit->get_caret_column();
	_text_submitted(p_string);
	
	line_edit->set_caret_column(cursor_pos);
}
LineEdit *SpinBox::get_line_edit() {