### 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
button_hist_next->set_icon(get_theme_icon(SNAME("Back"), SNAME("EditorIcons")));
				button_hist_prev->set_icon(get_theme_icon(SNAME("Forward"), SNAME("EditorIcons")));
			} else {
				button_hist_next->set_icon(get_theme_icon(SNAME("Forward"), SNAME("EditorIcons")));
				button_hist_prev->set_icon(get_theme_icon(SNAME("Back"), SNAME("EditorIcons")));
			}
			file_list_popup->connect("id_pressed", callable_mp(this, &FileSystemDock::_file_list_rmb_option));
			tree_popup->connect("id_pressed", callable_mp(this, &FileSystemDock::_tree_rmb_option));
			current_path_line_edit->connect("text_submitted", callable_mp(this, &FileSystemDock::_navigate_to_path).bind(false));
			always_show_folders = bool(EDITOR_GET("docks/filesystem/always_show_folders"));
			set_file_list_display_mode(FileSystemDock::FILE_LIST_DISPLAY_LIST);
			_update_display_mode();
			if (EditorFileSystem::get_singleton()->is_scanning()) {
				_set_scanning_mode();
			} else {
				_update_tree(Vector<String>(), true);
			}
		} break;
		case NOTIFICATION_PROCESS: {
			if (EditorFileSystem::get_singleton()->is_scanning()) {
				scanning_progress->set_value(EditorFileSystem::get_singleton()->get_scanning_progress() * 100);
			}
		} break;
		case NOTIFICATION_DRAG_BEGIN: {
			Dictionary dd = get_viewport()->gui_get_drag_data();
			if (tree->is_visible_in_tree() && dd.has("type")) {
				if (dd.has("favorite")) {
					if ((String(dd["favorite"]) == "all")) {
						tree->set_drop_mode_flags(Tree::DROP_MODE_INBETWEEN);
					}