### 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)

PROJECTION_PERSPECTIVE,
			PROJECTION_ORTHOGONAL
		};
		Projection projection = Projection::PROJECTION_PERSPECTIVE;
		real_t fov = 0.0;
		real_t size = 0.0;
		real_t z_near = 0.0;
		real_t z_far = 0.0;
		RID rid;
		operator bool() const {
			return rid != RID();
		}
	} camera_3d_override;
	friend class Camera3D;
	Camera3D *camera_3d = nullptr;
	HashSet<Camera3D *> camera_3d_set;
	Camera3D *get_camera_3d() const;
	void _camera_3d_transform_changed_notify();
	void _camera_3d_set(Camera3D *p_camera);