### 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)

bool is_input_handled() const;
	void set_handle_input_locally(bool p_enable);
	bool is_handling_input_locally() const;
	bool gui_is_dragging() const;
	bool gui_is_drag_successful() const;
	Control *gui_find_control(const Point2 &p_global);
	void set_sdf_oversize(SDFOversize p_sdf_oversize);
	SDFOversize get_sdf_oversize() const;
	void set_sdf_scale(SDFScale p_sdf_scale);
	SDFScale get_sdf_scale() const;
	void set_default_canvas_item_texture_filter(DefaultCanvasItemTextureFilter p_filter);
	DefaultCanvasItemTextureFilter get_default_canvas_item_texture_filter() const;
	void set_default_canvas_item_texture_repeat(DefaultCanvasItemTextureRepeat p_repeat);
	DefaultCanvasItemTextureRepeat get_default_canvas_item_texture_repeat() const;
	
	void set_vrs_mode(VRSMode p_vrs_mode);
	VRSMode get_vrs_mode() const;
	void set_vrs_texture(Ref<Texture2D> p_texture);
	Ref<Texture2D> get_vrs_texture() const;
	virtual DisplayServer::WindowID get_window_id() const = 0;
	void set_embedding_subwindows(bool p_embed);
	bool is_embedding_subwindows() const;
	Viewport *get_parent_viewport() const;
	Window *get_base_window() const;
	void pass_mouse_focus_to(Viewport *p_viewport, Control *p_control);
	void set_canvas_cull_mask(uint32_t p_layers);
	uint32_t get_canvas_cull_mask() const;
	void set_canvas_cull_mask_bit(uint32_t p_layer, bool p_enable);
	bool get_canvas_cull_mask_bit(uint32_t p_layer) const;
	virtual bool is_size_2d_override_stretch_enabled() const { return true; }