### 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)
}
			if (ED_IS_SHORTCUT("file_dialog/refresh", p_event)) {
				invalidate();
				handled = true;
			}
			if (ED_IS_SHORTCUT("file_dialog/toggle_hidden_files", p_event)) {
				set_show_hidden_files(!show_hidden_files);
				handled = true;
			}
			if (ED_IS_SHORTCUT("file_dialog/toggle_favorite", p_event)) {
				_favorite_pressed();
				handled = true;
			}
			if (ED_IS_SHORTCUT("file_dialog/toggle_mode", p_event)) {
				if (mode_thumbnails->is_pressed()) {
					set_display_mode(DISPLAY_LIST);
				} else {
					set_display_mode(DISPLAY_THUMBNAILS);
				}
				handled = true;
			}
			if (ED_IS_SHORTCUT("file_dialog/create_folder", p_event)) {
				_make_dir();
				handled = true;
			}
			if (ED_IS_SHORTCUT("file_dialog/delete", p_event)) {
				_delete_items();
				handled = true;
			}
			if (ED_IS_SHORTCUT("file_dialog/focus_path", p_event)) {