### 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
String new_name = duplicate_dialog_text->get_text().strip_edges();
	if (new_name.length() == 0) {
		EditorNode::get_singleton()->show_warning(TTR("No name provided."));
		return;
	} else if (new_name.contains("/") || new_name.contains("\\") || new_name.contains(":")) {
		EditorNode::get_singleton()->show_warning(TTR("Name contains invalid characters."));
		return;
	}
	String base_dir = to_duplicate.path.get_base_dir();
	
	if (to_duplicate.path.ends_with("/")) {
		base_dir = base_dir.get_base_dir();
	}
	String new_path = base_dir.path_join(new_name);
	
	Ref<DirAccess> da = DirAccess::create(DirAccess::ACCESS_RESOURCES);
	if (da->file_exists(new_path) || da->dir_exists(new_path)) {
		EditorNode::get_singleton()->show_warning(TTR("A file or folder with this name already exists."));
		return;
	}
	_try_duplicate_item(to_duplicate, new_path);
	
	print_verbose("FileSystem: calling rescan.");
	_rescan();
}
void FileSystemDock::_overwrite_dialog_action(bool p_overwrite) {