### 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)
case EditorSettings::NOTIFICATION_EDITOR_SETTINGS_CHANGED: {
			bool is_showing_hidden = EDITOR_GET("filesystem/file_dialog/show_hidden_files");
			if (show_hidden_files != is_showing_hidden) {
				set_show_hidden_files(is_showing_hidden);
			}
			set_display_mode((DisplayMode)EDITOR_GET("filesystem/file_dialog/display_mode").operator int());
			
			invalidate();
		} break;
		case NOTIFICATION_VISIBILITY_CHANGED: {
			if (!is_visible()) {
				set_process_shortcut_input(false);
			}
			invalidate(); 
		} break;
		case NOTIFICATION_WM_WINDOW_FOCUS_IN: {
			
			String previous_dir = get_current_dir();
			while (!dir_access->dir_exists(get_current_dir())) {
				_go_up();
				
				if (get_current_dir() == previous_dir) {
					_dir_submitted(OS::get_singleton()->get_user_data_dir());
					break;
				}
			}
		} break;
	}
}
void EditorFileDialog::shortcut_input(const Ref<InputEvent> &p_event) {