### 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)
disable_overwrite_warning = p_disable;
}
bool EditorFileDialog::is_overwrite_warning_disabled() const {
	return disable_overwrite_warning;
}
void EditorFileDialog::set_previews_enabled(bool p_enabled) {
	previews_enabled = p_enabled;
}
bool EditorFileDialog::are_previews_enabled() {
	return previews_enabled;
}
EditorFileDialog::EditorFileDialog() {
	show_hidden_files = default_show_hidden_files;
	display_mode = default_display_mode;
	VBoxContainer *vbc = memnew(VBoxContainer);
	add_child(vbc);
	set_title(TTR("Save a File"));
	ED_SHORTCUT("file_dialog/go_back", TTR("Go Back"), KeyModifierMask::ALT | Key::LEFT);
	ED_SHORTCUT("file_dialog/go_forward", TTR("Go Forward"), KeyModifierMask::ALT | Key::RIGHT);
	ED_SHORTCUT("file_dialog/go_up", TTR("Go Up"), KeyModifierMask::ALT | Key::UP);
	ED_SHORTCUT("file_dialog/refresh", TTR("Refresh"), Key::F5);