### Godot version

v4.1.rc2.official [46424488e]

### System information

Godot v4.1.rc2 - Linux Mint 20 (Ulyana) - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2060 SUPER (nvidia; 515.105.01) - Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz (8 Threads)

### Issue description

Dragging and dropping a file to a new position inside its current folder, or onto the icon for its current folder - when that folder is the project root folder :res// - will be treated as though you were dropping a different file with the same name.

Expectation: for nothing to happen.

Also tried it in 4.0.3 and 4.1-dev3, where it behaves as expected.

https://github.com/godotengine/godot/assets/64640811/90de1120-dd92-41b8-b202-db77c343103a

### Steps to reproduce

1. New or existing project.
2. Click and drag a file in :res// in FileSystem dock.
3. Drop the file back into :res//.
4. Be prompted to overwrite or rename.

### Minimal reproduction project

N/A
continue;
		}
		Ref<Texture2D> folder_icon = get_theme_icon(SNAME("Folder"), SNAME("EditorIcons"));
		const Color folder_color = get_theme_color(SNAME("folder_icon_color"), SNAME("FileDialog"));
		String text;
		Ref<Texture2D> icon;
		Color color;
		if (favorite == "res://") {
			text = "/";
			icon = folder_icon;
			color = folder_color;
		} else if (favorite.ends_with("/")) {
			text = favorite.substr(0, favorite.length() - 1).get_file();
			icon = folder_icon;
			color = folder_color;
		} else {
			text = favorite.get_file();
			int index;
			EditorFileSystemDirectory *dir = EditorFileSystem::get_singleton()->find_file(favorite, &index);
			if (dir) {
				icon = _get_tree_item_icon(dir->get_file_import_is_valid(index), dir->get_file_type(index));
			} else {
				icon = get_theme_icon(SNAME("File"), SNAME("EditorIcons"));
			}
			color = Color(1, 1, 1);
		}
		if (searched_string.length() == 0 || text.to_lower().find(searched_string) >= 0) {
			TreeItem *ti = tree->create_item(favorites_item);
			ti->set_text(0, text);
			ti->set_icon(0, icon);