### 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
Ref<DirAccess> da = DirAccess::create(DirAccess::ACCESS_RESOURCES);
#if defined(WINDOWS_ENABLED) || defined(UWP_ENABLED)
	
	if ((da->file_exists(new_path) || da->dir_exists(new_path)) && new_path.to_lower() != old_path.to_lower()) {
#else
	if (da->file_exists(new_path) || da->dir_exists(new_path)) {
#endif
		EditorNode::get_singleton()->show_warning(TTR("A file or folder with this name already exists."));
		s->set_text(col_index, old_name);
		return;
	}
	HashMap<String, String> file_renames;
	HashMap<String, String> folder_renames;
	_try_move_item(to_rename, new_path, file_renames, folder_renames);
	int current_tab = EditorNode::get_singleton()->get_current_tab();
	_save_scenes_after_move(file_renames); 
	_update_dependencies_after_move(file_renames);
	_update_resource_paths_after_move(file_renames);
	_update_project_settings_after_move(file_renames);
	_update_favorites_list_after_move(file_renames, folder_renames);
	EditorNode::get_singleton()->set_current_tab(current_tab);
	print_verbose("FileSystem: calling rescan.");
	_rescan();
	print_verbose("FileSystem: saving moved scenes.");
	_save_scenes_after_move(file_renames);
	current_path = new_path;
	current_path_line_edit->set_text(current_path);
}
void FileSystemDock::_duplicate_operation_confirm() {