### 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)

DEBUG_DRAW_DISABLED,
		DEBUG_DRAW_UNSHADED,
		DEBUG_DRAW_LIGHTING,
		DEBUG_DRAW_OVERDRAW,
		DEBUG_DRAW_WIREFRAME,
		DEBUG_DRAW_NORMAL_BUFFER,
		DEBUG_DRAW_VOXEL_GI_ALBEDO,
		DEBUG_DRAW_VOXEL_GI_LIGHTING,
		DEBUG_DRAW_VOXEL_GI_EMISSION,
		DEBUG_DRAW_SHADOW_ATLAS,
		DEBUG_DRAW_DIRECTIONAL_SHADOW_ATLAS,
		DEBUG_DRAW_SCENE_LUMINANCE,
		DEBUG_DRAW_SSAO,
		DEBUG_DRAW_SSIL,
		DEBUG_DRAW_PSSM_SPLITS,
		DEBUG_DRAW_DECAL_ATLAS,
		DEBUG_DRAW_SDFGI,
		DEBUG_DRAW_SDFGI_PROBES,
		DEBUG_DRAW_GI_BUFFER,
		DEBUG_DRAW_DISABLE_LOD,
		DEBUG_DRAW_CLUSTER_OMNI_LIGHTS,
		DEBUG_DRAW_CLUSTER_SPOT_LIGHTS,
		DEBUG_DRAW_CLUSTER_DECALS,
		DEBUG_DRAW_CLUSTER_REFLECTION_PROBES,
		DEBUG_DRAW_OCCLUDERS,
		DEBUG_DRAW_MOTION_VECTORS,
	};
	enum DefaultCanvasItemTextureFilter {