### 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 (drives->is_visible()) {
		if (dir_access->get_current_dir().is_network_share_path()) {
			_update_drives(false);
			drives->add_item(RTR("Network"));
			drives->set_item_disabled(-1, true);
			drives->select(drives->get_item_count() - 1);
		} else {
			drives->select(dir_access->get_current_drive());
		}
	}
	dir->set_text(dir_access->get_current_dir(false));
	file->set_text("");
	
	get_ok_button()->set_disabled(_is_open_should_be_disabled());
	switch (mode) {
		case FILE_MODE_OPEN_FILE:
		case FILE_MODE_OPEN_FILES:
			set_ok_button_text(TTR("Open"));
			break;
		case FILE_MODE_OPEN_ANY:
		case FILE_MODE_OPEN_DIR:
			set_ok_button_text(TTR("Select Current Folder"));
			break;
		case FILE_MODE_SAVE_FILE:
			
			break;
	}
}
void EditorFileDialog::_dir_submitted(String p_dir) {