### Godot version

v4.0.beta17.mono.official [c40020513]

### System information

Window 11, Forward+, GTX 1060

### Issue description

Adding two theme variations in a row result to a  crash.

https://user-images.githubusercontent.com/93253123/217037249-1ce1d56d-beb6-4435-83ad-9f8a07fe0e96.mp4



### Steps to reproduce

1. Create a project.
2. Create a theme.
3. Double click to go in the theme editor.
4. Click on manage items buttons.
5. In the add type field type a name to add a type.
6. type another name to add a second type.
7. Crash.

### Minimal reproduction project

[ThemeVariationCrash.zip](https://github.com/godotengine/godot/files/10665863/ThemeVariationCrash.zip)

#include "editor_inspector.h"
#include "core/os/keyboard.h"
#include "editor/doc_tools.h"
#include "editor/editor_feature_profile.h"
#include "editor/editor_node.h"
#include "editor/editor_property_name_processor.h"
#include "editor/editor_scale.h"
#include "editor/editor_settings.h"
#include "editor/editor_undo_redo_manager.h"
#include "editor/inspector_dock.h"
#include "editor/plugins/script_editor_plugin.h"
#include "multi_node_edit.h"
#include "scene/gui/spin_box.h"
#include "scene/gui/texture_rect.h"
#include "scene/property_utils.h"
#include "scene/resources/packed_scene.h"
static bool _property_path_matches(const String &p_property_path, const String &p_filter, EditorPropertyNameProcessor::Style p_style) {