### 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)

DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_DISABLED,
		DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_ENABLED,
		DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_MIRROR,
		DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_MAX,
	};
	enum SDFOversize {
		SDF_OVERSIZE_100_PERCENT,
		SDF_OVERSIZE_120_PERCENT,
		SDF_OVERSIZE_150_PERCENT,
		SDF_OVERSIZE_200_PERCENT,
		SDF_OVERSIZE_MAX
	};
	enum SDFScale {
		SDF_SCALE_100_PERCENT,
		SDF_SCALE_50_PERCENT,
		SDF_SCALE_25_PERCENT,
		SDF_SCALE_MAX
	};
	enum {
		SUBWINDOW_CANVAS_LAYER = 1024
	};
	enum VRSMode {
		VRS_DISABLED,
		VRS_TEXTURE,