### 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)

camera_3d_set.insert(p_camera);
	return camera_3d_set.size() == 1;
}
void Viewport::_camera_3d_remove(Camera3D *p_camera) {
	camera_3d_set.erase(p_camera);
	if (camera_3d == p_camera) {
		camera_3d->notification(Camera3D::NOTIFICATION_LOST_CURRENT);
		camera_3d = nullptr;
	}
}
void Viewport::_camera_3d_make_next_current(Camera3D *p_exclude) {
	for (Camera3D *E : camera_3d_set) {
		if (p_exclude == E) {
			continue;
		}
		if (!E->is_inside_tree()) {
			continue;
		}
		if (camera_3d != nullptr) {
			return;
		}
		E->make_current();
	}
}
void Viewport::enable_camera_3d_override(bool p_enable) {