### 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
_move_operation_confirm(p_path, move_dialog->is_copy_pressed());
}
void FileSystemDock::_move_operation_confirm(const String &p_to_path, bool p_copy, Overwrite p_overwrite) {
	if (p_overwrite == OVERWRITE_UNDECIDED) {
		to_move_path = p_to_path;
		to_move_or_copy = p_copy;
		Vector<String> conflicting_items = _check_existing();
		if (!conflicting_items.is_empty()) {
			
			overwrite_dialog_header->set_text(vformat(
					TTR("The following files or folders conflict with items in the target location '%s':"), to_move_path));
			overwrite_dialog_file_list->set_text(String("\n").join(conflicting_items));
			overwrite_dialog_footer->set_text(
					p_copy ? TTR("Do you wish to overwrite them or rename the copied files?")
						   : TTR("Do you wish to overwrite them or rename the moved files?"));
			overwrite_dialog->popup_centered();
			return;
		}
	}
	Vector<String> new_paths;
	new_paths.resize(to_move.size());
	for (int i = 0; i < to_move.size(); i++) {
		if (p_overwrite == OVERWRITE_RENAME) {
			new_paths.write[i] = _get_unique_name(to_move[i], p_to_path);