### 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)

_update_viewport_path();
		} break;
		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
			if (!get_tree()) {
				return;
			}
			if (get_tree()->is_debugging_collisions_hint() && contact_2d_debug.is_valid()) {
				RenderingServer::get_singleton()->canvas_item_clear(contact_2d_debug);
				RenderingServer::get_singleton()->canvas_item_set_draw_index(contact_2d_debug, 0xFFFFF); 
				Vector<Vector2> points = PhysicsServer2D::get_singleton()->space_get_contacts(find_world_2d()->get_space());
				int point_count = PhysicsServer2D::get_singleton()->space_get_contact_count(find_world_2d()->get_space());
				Color ccol = get_tree()->get_debug_collision_contact_color();
				for (int i = 0; i < point_count; i++) {
					RenderingServer::get_singleton()->canvas_item_add_rect(contact_2d_debug, Rect2(points[i] - Vector2(2, 2), Vector2(5, 5)), ccol);
				}
			}
#ifndef _3D_DISABLED
			if (get_tree()->is_debugging_collisions_hint() && contact_3d_debug_multimesh.is_valid()) {
				Vector<Vector3> points = PhysicsServer3D::get_singleton()->space_get_contacts(find_world_3d()->get_space());
				int point_count = PhysicsServer3D::get_singleton()->space_get_contact_count(find_world_3d()->get_space());
				RS::get_singleton()->multimesh_set_visible_instances(contact_3d_debug_multimesh, point_count);
				for (int i = 0; i < point_count; i++) {
					Transform3D point_transform;
					point_transform.origin = points[i];
					RS::get_singleton()->multimesh_instance_set_transform(contact_3d_debug_multimesh, i, point_transform);
				}
			}
#endif 
		} break;
		case NOTIFICATION_VP_MOUSE_ENTER: {