### Godot version

4.1.1

### System information

linux

### Issue description

- When favoriting a path in a `FileDialog`, clicking on it travels to `path/to/dir/`.
- When going up a level from there, it doesn't go to `path/to` but to `path/to/dir` (without the `/`).

[simplescreenrecorder-2023-08-18_09.38.37.webm](https://github.com/godotengine/godot/assets/71937306/00c20ad3-292f-4961-84ed-dbc64906df52)

The problem is either (or both) that:
 - loaded path has a trailing `/`
 - parent dir of `stuff/` is considered to be `stuff`

### Steps to reproduce

favorite a directory and use the feature to navigate to it

### Minimal reproduction project

any (i.e. the project manager's "new project" dialog has one)
switch (p_option) {
		case ITEM_MENU_COPY_PATH: {
			Dictionary item_meta = item_list->get_item_metadata(item_list->get_current());
			DisplayServer::get_singleton()->clipboard_set(item_meta["path"]);
		} break;
		case ITEM_MENU_DELETE: {
			_delete_items();
		} break;
		case ITEM_MENU_REFRESH: {
			invalidate();
		} break;
		case ITEM_MENU_NEW_FOLDER: {
			_make_dir();
		} break;
		case ITEM_MENU_SHOW_IN_EXPLORER: {
			String path;
			int idx = item_list->get_current();
			if (idx == -1 || item_list->get_selected_items().size() == 0) {
				
				path = ProjectSettings::get_singleton()->globalize_path(dir_access->get_current_dir());
			} else {
				
				Dictionary item_meta = item_list->get_item_metadata(idx);
				path = ProjectSettings::get_singleton()->globalize_path(item_meta["path"]);
			}
			OS::get_singleton()->shell_show_in_file_manager(path, true);
		} break;
	}
}
bool EditorFileDialog::_is_open_should_be_disabled() {