### 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)
for (int i = 0; i < item_list->get_item_count(); i++) {
		if (!item_list->is_selected(i)) {
			continue;
		}
		Dictionary item_meta = item_list->get_item_metadata(i);
		
		dir_access->remove(item_meta["path"]);
	}
	update_file_list();
}
void EditorFileDialog::_select_drive(int p_idx) {