### 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)

int a = 0;
	int b = 1;
	while (sections_to_unfold[a].size()) {
		for (EditorInspectorSection *E : sections_to_unfold[a]) {
			E->unfold();
			Node *n = E->get_parent();
			while (n) {
				if (Object::cast_to<EditorInspector>(n)) {
					break;
				}
				if (Object::cast_to<EditorInspectorSection>(n) && !sections_to_unfold[a].has((EditorInspectorSection *)n)) {
					sections_to_unfold[b].insert((EditorInspectorSection *)n);
				}
				n = n->get_parent();
			}
		}
		sections_to_unfold[a].clear();
		SWAP(a, b);
	}
	for (const KeyValue<StringName, List<EditorProperty *>> &F : editor_property_map) {
		for (EditorProperty *E : F.value) {
			E->expand_revertable();
		}
	}
}
void EditorInspector::set_scroll_offset(int p_offset) {
	set_v_scroll(p_offset);
}
int EditorInspector::get_scroll_offset() const {