### 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)

for (EditorProperty *E : editor_property_map[p_path]) {
				E->set_checked(p_checked);
				E->update_property();
				E->update_editor_property_status();
				E->update_cache();
			}
		}
	} else {
		emit_signal(SNAME("property_toggled"), p_path, p_checked);
	}
}
void EditorInspector::_property_pinned(const String &p_path, bool p_pinned) {
	if (!object) {
		return;
	}
	Node *node = Object::cast_to<Node>(object);
	ERR_FAIL_COND(!node);
	EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
	undo_redo->create_action(vformat(p_pinned ? TTR("Pinned %s") : TTR("Unpinned %s"), p_path));
	undo_redo->add_do_method(node, "_set_property_pinned", p_path, p_pinned);
	undo_redo->add_undo_method(node, "_set_property_pinned", p_path, !p_pinned);
	if (editor_property_map.has(p_path)) {
		for (List<EditorProperty *>::Element *E = editor_property_map[p_path].front(); E; E = E->next()) {
			undo_redo->add_do_method(E->get(), "_update_editor_property_status");
			undo_redo->add_undo_method(E->get(), "_update_editor_property_status");
		}
	}
	undo_redo->commit_action();
}
void EditorInspector::_property_selected(const String &p_path, int p_focusable) {