### 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)

}
			
			undo_redo->add_do_property(object, count_property, properties_as_array.size());
			for (int i = 0; i < (int)properties_as_array.size(); i++) {
				Dictionary d = properties_as_array[i];
				Array keys = d.keys();
				for (int j = 0; j < keys.size(); j++) {
					String key = keys[j];
					undo_redo->add_do_property(object, vformat(key, i), d[key]);
				}
			}
		}
	}
	undo_redo->commit_action();
	
	if (p_element_index < 0) {
		int added_index = p_to_pos < 0 ? count : p_to_pos;
		emit_signal(SNAME("page_change_request"), added_index / page_length);
		count += 1;
	} else if (p_to_pos < 0) {
		count -= 1;
		if (page == max_page && (MAX(0, count - 1) / page_length != max_page)) {
			emit_signal(SNAME("page_change_request"), max_page - 1);
		}
	}
	begin_array_index = page * page_length;
	end_array_index = MIN(count, (page + 1) * page_length);
	max_page = MAX(0, count - 1) / page_length;
}
void EditorInspectorArray::_clear_array() {