### 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)

ERR_MAIN_THREAD_GUARD;
	if (p_disable == disable_input) {
		return;
	}
	if (p_disable) {
		_drop_mouse_focus();
		_drop_mouse_over();
		_gui_cancel_tooltip();
	}
	disable_input = p_disable;
}
bool Viewport::is_input_disabled() const {
	ERR_READ_THREAD_GUARD_V(false);
	return disable_input;
}
Variant Viewport::gui_get_drag_data() const {
	ERR_READ_THREAD_GUARD_V(Variant());
	return gui.drag_data;
}
PackedStringArray Viewport::get_configuration_warnings() const {
	ERR_MAIN_THREAD_GUARD_V(PackedStringArray());
	PackedStringArray warnings = Node::get_configuration_warnings();
	if (size.x <= 1 || size.y <= 1) {
		warnings.push_back(RTR("The Viewport size must be greater than or equal to 2 pixels on both dimensions to render anything."));
	}
	return warnings;
}
void Viewport::gui_reset_canvas_sort_index() {