### 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 (!is_visible() || is_invalidating) {
		return;
	}
	is_invalidating = true;
	callable_mp(this, &EditorFileDialog::_invalidate).call_deferred();
}
void EditorFileDialog::_invalidate() {
	if (!is_invalidating) {
		return;
	}
	update_file_list();
	_update_favorites();
	_update_recent();
	is_invalidating = false;
}
EditorFileDialog::Access EditorFileDialog::get_access() const {