### 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
if (p_button != MouseButton::RIGHT) {
		return;
	}
	
	Vector<String> paths = _tree_get_selected(false);
	tree_popup->clear();
	
	if (!paths.is_empty()) {
		tree_popup->reset_size();
		_file_and_folders_fill_popup(tree_popup, paths);
		tree_popup->set_position(tree->get_screen_position() + p_pos);
		tree_popup->reset_size();
		tree_popup->popup();
	}
}
void FileSystemDock::_tree_empty_click(const Vector2 &p_pos, MouseButton p_button) {