### 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)

}
		if (over != gui.mouse_over) {
			_drop_mouse_over();
			_gui_cancel_tooltip();
			if (over) {
				if (!gui.mouse_over) {
					_drop_physics_mouseover();
				}
				_gui_call_notification(over, Control::NOTIFICATION_MOUSE_ENTER);
				gui.mouse_over = over;
			}
		}
		if (gui.mouse_focus) {
			over = gui.mouse_focus;
		}
		DisplayServer::CursorShape ds_cursor_shape = (DisplayServer::CursorShape)Input::get_singleton()->get_default_cursor_shape();
		if (over) {
			Transform2D localizer = over->get_global_transform_with_canvas().affine_inverse();
			Size2 pos = localizer.xform(mpos);
			Vector2 velocity = localizer.basis_xform(mm->get_velocity());
			Vector2 rel = localizer.basis_xform(mm->get_relative());
			mm = mm->xformed_by(Transform2D()); 
			mm->set_global_position(mpos);
			mm->set_velocity(velocity);
			mm->set_relative(rel);
			if (mm->get_button_mask().is_empty()) {
				
				bool is_tooltip_shown = false;
				if (gui.tooltip_popup) {
					if (gui.tooltip_control) {