### 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)

select_colors_label->set_text(TTRN("1 color", "{num} colors", color_amount).format(arr, "{num}"));
		select_all_colors_button->set_visible(true);
		select_full_colors_button->set_visible(true);
		deselect_all_colors_button->set_visible(true);
	} else {
		select_colors_label->set_text(TTR("No colors found."));
		select_all_colors_button->set_visible(false);
		select_full_colors_button->set_visible(false);
		deselect_all_colors_button->set_visible(false);
	}
	if (constant_amount > 0) {
		Array arr;
		arr.push_back(constant_amount);
		select_constants_label->set_text(TTRN("1 constant", "{num} constants", constant_amount).format(arr, "{num}"));
		select_all_constants_button->set_visible(true);
		select_full_constants_button->set_visible(true);
		deselect_all_constants_button->set_visible(true);
	} else {
		select_constants_label->set_text(TTR("No constants found."));
		select_all_constants_button->set_visible(false);
		select_full_constants_button->set_visible(false);
		deselect_all_constants_button->set_visible(false);
	}
	if (font_amount > 0) {
		Array arr;
		arr.push_back(font_amount);
		select_fonts_label->set_text(TTRN("1 font", "{num} fonts", font_amount).format(arr, "{num}"));
		select_all_fonts_button->set_visible(true);
		select_full_fonts_button->set_visible(true);
		deselect_all_fonts_button->set_visible(true);