### Godot version

4.0.3.stable

### System information

Windows 10/11

### Issue description

I want the player's cursor to change when highlighting pickable Area2Ds; to do this, I have the areas modify the `mouse_default_cursor_shape` property on an external Control when the mouse enters or exits. If another Control appears in front of the Area2D while the mouse is over it, there is a chance that the project will crash.

Nothing prints to the IDE's output on this crash. If running the editor with console, then
```
ERROR: Condition "slot >= slot_max" is true. Returning: nullptr
   at: get_instance (./core/object/object.h:972)
```
will sometimes appear alongside the crash. If it appears, it always appears twice.

When I run a debug build of the editor through WinDbg, WinDbg will catch the following exception:
```
(3b58.2aac): Access violation - code c0000005 (!!! second chance !!!)
godot_windows_editor_x86_64!ObjectDB::get_instance [inlined in godot_windows_editor_x86_64!Viewport::_cleanup_mouseover_colliders+0x6f]:
00007ff6`ac254a1f 488b5310        mov     rdx,qword ptr [rbx+10h] ds:cccccccc`c31c419b=????????????????
```
When using this method, the exception is not random; it always occurs on the first attempt.

### Steps to reproduce

- Open the minimal reproduction project in the editor.
- Run the project.
- Click on the Area2D (you'll want visible collision shapes on).
- A full-screen button will pop up. If the game does not crash at this point, clicking the button will hide it so you can try again. It should crash within a few seconds of mashing.

### Minimal reproduction project

[Crash Test.zip](https://github.com/godotengine/godot/files/12027772/Crash.Test.zip)

ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "world_2d", PROPERTY_HINT_RESOURCE_TYPE, "World2D", PROPERTY_USAGE_NONE), "set_world_2d", "get_world_2d");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "transparent_bg"), "set_transparent_background", "has_transparent_background");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "handle_input_locally"), "set_handle_input_locally", "is_handling_input_locally");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "snap_2d_transforms_to_pixel"), "set_snap_2d_transforms_to_pixel", "is_snap_2d_transforms_to_pixel_enabled");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "snap_2d_vertices_to_pixel"), "set_snap_2d_vertices_to_pixel", "is_snap_2d_vertices_to_pixel_enabled");
	ADD_GROUP("Rendering", "");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "msaa_2d", PROPERTY_HINT_ENUM, String::utf8("Disabled (Fastest),2× (Average),4× (Slow),8× (Slowest)")), "set_msaa_2d", "get_msaa_2d");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "msaa_3d", PROPERTY_HINT_ENUM, String::utf8("Disabled (Fastest),2× (Average),4× (Slow),8× (Slowest)")), "set_msaa_3d", "get_msaa_3d");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "screen_space_aa", PROPERTY_HINT_ENUM, "Disabled (Fastest),FXAA (Fast)"), "set_screen_space_aa", "get_screen_space_aa");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_taa"), "set_use_taa", "is_using_taa");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_debanding"), "set_use_debanding", "is_using_debanding");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_occlusion_culling"), "set_use_occlusion_culling", "is_using_occlusion_culling");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "mesh_lod_threshold", PROPERTY_HINT_RANGE, "0,1024,0.1"), "set_mesh_lod_threshold", "get_mesh_lod_threshold");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "debug_draw", PROPERTY_HINT_ENUM, "Disabled,Unshaded,Lighting,Overdraw,Wireframe"), "set_debug_draw", "get_debug_draw");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_hdr_2d"), "set_use_hdr_2d", "is_using_hdr_2d");
#ifndef _3D_DISABLED
	ADD_GROUP("Scaling 3D", "");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "scaling_3d_mode", PROPERTY_HINT_ENUM, "Bilinear (Fastest),FSR 1.0 (Fast)"), "set_scaling_3d_mode", "get_scaling_3d_mode");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "scaling_3d_scale", PROPERTY_HINT_RANGE, "0.25,2.0,0.01"), "set_scaling_3d_scale", "get_scaling_3d_scale");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "texture_mipmap_bias", PROPERTY_HINT_RANGE, "-2,2,0.001"), "set_texture_mipmap_bias", "get_texture_mipmap_bias");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "fsr_sharpness", PROPERTY_HINT_RANGE, "0,2,0.1"), "set_fsr_sharpness", "get_fsr_sharpness");
#endif
	ADD_GROUP("Variable Rate Shading", "vrs_");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "vrs_mode", PROPERTY_HINT_ENUM, "Disabled,Texture,Depth buffer,XR"), "set_vrs_mode", "get_vrs_mode");
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "vrs_texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture2D"), "set_vrs_texture", "get_vrs_texture");
	ADD_GROUP("Canvas Items", "canvas_item_");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_filter", PROPERTY_HINT_ENUM, "Nearest,Linear,Linear Mipmap,Nearest Mipmap"), "set_default_canvas_item_texture_filter", "get_default_canvas_item_texture_filter");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "canvas_item_default_texture_repeat", PROPERTY_HINT_ENUM, "Disabled,Enabled,Mirror"), "set_default_canvas_item_texture_repeat", "get_default_canvas_item_texture_repeat");
	ADD_GROUP("Audio Listener", "audio_listener_");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "audio_listener_enable_2d"), "set_as_audio_listener_2d", "is_audio_listener_2d");