### 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 (!list_items_selected_on_drag_begin.is_empty()) {
		for (const int idx : list_items_selected_on_drag_begin) {
			files->select(idx, false);
		}
		if (reset) {
			list_items_selected_on_drag_begin.clear();
		}
	}
}
void FileSystemDock::_tree_gui_input(Ref<InputEvent> p_event) {
	Ref<InputEventKey> key = p_event;
	Ref<InputEventMouseMotion> mm = p_event;
	if (mm.is_valid()) {
		TreeItem *item = tree->get_item_at_position(mm->get_position());
		if (item && holding_branch) {
			String fpath = item->get_metadata(0);
			while (!fpath.ends_with("/") && fpath != "res://" && item->get_parent()) { 
				item = item->get_parent();
				fpath = item->get_metadata(0);
			}
			TreeItem *deselect_item = tree->get_next_selected(tree->get_root());
			while (deselect_item) {
				deselect_item->deselect(0);
				deselect_item = tree->get_next_selected(deselect_item);
			}
			item->select(0);
			if (display_mode == DisplayMode::DISPLAY_MODE_SPLIT) {
				files->deselect_all();
				
				const int files_item_idx = files->find_metadata(fpath);