### Tested versions

Caused by [0d6300d269b818e6c3d3ea9cbc592480103aa6d0] Fix folder color not showing up in file dialogs
https://github.com/godotengine/godot/pull/84837
(git bisection)

### System information

Godot v4.3.dev (6faa5c6dc) - Fedora Linux 39 (Workstation Edition) - Wayland - Vulkan (Forward+) - dedicated AMD Radeon RX Vega (RADV VEGA10) () - AMD Ryzen 7 5800X 8-Core Processor (16 Threads)

### Issue description

When opening the export path, it results in a black popup.

![image](https://github.com/godotengine/godot/assets/270928/d67dee6a-f1e1-4bf3-8a3f-419554269f4a)


### Steps to reproduce

1. Open export settings
2. Add an export target
3. Try to select an export path

### Minimal reproduction project (MRP)

n/a
const HashMap<String, Color> &folder_colors = FileSystemDock::get_singleton()->get_folder_colors();
	Dictionary assigned_folder_colors = FileSystemDock::get_singleton()->get_assigned_folder_colors();
	Color folder_icon_color = theme_cache.folder_icon_color;
	
	String parent_dir = p_dir_path;
	while (parent_dir != "res://" && folder_icon_color == theme_cache.folder_icon_color) {
		if (!parent_dir.ends_with("/")) {
			parent_dir += "/";
		}
		if (assigned_folder_colors.has(parent_dir)) {
			folder_icon_color = folder_colors[assigned_folder_colors[parent_dir]];
		}
		parent_dir = parent_dir.trim_suffix("/").get_base_dir();
	}
	return folder_icon_color;
}
void EditorFileDialog::update_file_list() {