### 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 (filter->get_selected() == filter->get_item_count() - 1) {
		
	} else if (filters.size() > 1 && filter->get_selected() == 0) {
		
		for (int i = 0; i < filters.size(); i++) {
			String f = filters[i].get_slice(";", 0);
			for (int j = 0; j < f.get_slice_count(","); j++) {
				patterns.push_back(f.get_slice(",", j).strip_edges());
			}
		}
	} else {
		int idx = filter->get_selected();
		if (filters.size() > 1) {
			idx--;
		}
		if (idx >= 0 && idx < filters.size()) {
			String f = filters[idx].get_slice(";", 0);
			for (int j = 0; j < f.get_slice_count(","); j++) {
				patterns.push_back(f.get_slice(",", j).strip_edges());
			}
		}
	}
	while (!files.is_empty()) {
		bool match = patterns.is_empty();
		for (const String &E : patterns) {
			if (files.front()->get().matchn(E)) {
				match = true;
				break;
			}