### 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)

ADD_SIGNAL(MethodInfo("page_change_request"));
}
void EditorInspectorArray::setup_with_move_element_function(Object *p_object, String p_label, const StringName &p_array_element_prefix, int p_page, const Color &p_bg_color, bool p_foldable, bool p_movable, bool p_numbered, int p_page_length, const String &p_add_item_text) {
	count_property = "";
	mode = MODE_USE_MOVE_ARRAY_ELEMENT_FUNCTION;
	array_element_prefix = p_array_element_prefix;
	page = p_page;
	movable = p_movable;
	page_length = p_page_length;
	numbered = p_numbered;
	EditorInspectorSection::setup(String(p_array_element_prefix) + "_array", p_label, p_object, p_bg_color, p_foldable, 0);
	_setup();
}
void EditorInspectorArray::setup_with_count_property(Object *p_object, String p_label, const StringName &p_count_property, const StringName &p_array_element_prefix, int p_page, const Color &p_bg_color, bool p_foldable, bool p_movable, bool p_numbered, int p_page_length, const String &p_add_item_text, const String &p_swap_method) {
	count_property = p_count_property;
	mode = MODE_USE_COUNT_PROPERTY;
	array_element_prefix = p_array_element_prefix;
	page = p_page;
	movable = p_movable;
	page_length = p_page_length;
	numbered = p_numbered;
	swap_method = p_swap_method;
	add_button->set_text(p_add_item_text);
	EditorInspectorSection::setup(String(count_property) + "_array", p_label, p_object, p_bg_color, p_foldable, 0);
	_setup();
}
VBoxContainer *EditorInspectorArray::get_vbox(int p_index) {