### 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 (gui.subwindow_drag == SUB_WINDOW_DRAG_RESIZE) {
				Vector2i diff = mm->get_position() - gui.subwindow_drag_from;
				Size2i min_size = gui.subwindow_focused->get_min_size();
				Size2i min_size_clamped = gui.subwindow_focused->get_clamped_minimum_size();
				min_size_clamped.x = MAX(min_size_clamped.x, 1);
				min_size_clamped.y = MAX(min_size_clamped.y, 1);
				Rect2i r = gui.subwindow_resize_from_rect;
				Size2i limit = r.size - min_size_clamped;
				switch (gui.subwindow_resize_mode) {
					case SUB_WINDOW_RESIZE_TOP_LEFT: {
						diff.x = MIN(diff.x, limit.x);
						diff.y = MIN(diff.y, limit.y);
						r.position += diff;
						r.size -= diff;
					} break;
					case SUB_WINDOW_RESIZE_TOP: {
						diff.x = 0;
						diff.y = MIN(diff.y, limit.y);
						r.position += diff;
						r.size -= diff;
					} break;
					case SUB_WINDOW_RESIZE_TOP_RIGHT: {
						diff.x = MAX(diff.x, -limit.x);
						diff.y = MIN(diff.y, limit.y);
						r.position.y += diff.y;
						r.size.y -= diff.y;
						r.size.x += diff.x;
					} break;
					case SUB_WINDOW_RESIZE_LEFT: {