### 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_paths.size() > 1 || p_paths[0] != "res://") {
		p_popup->add_icon_item(get_theme_icon(SNAME("MoveUp"), SNAME("EditorIcons")), TTR("Move/Duplicate To..."), FILE_MOVE);
		p_popup->add_icon_shortcut(get_theme_icon(SNAME("Remove"), SNAME("EditorIcons")), ED_GET_SHORTCUT("filesystem_dock/delete"), FILE_REMOVE);
	}
	p_popup->add_separator();
	if (p_paths.size() >= 1) {
		if (!all_favorites) {
			p_popup->add_icon_item(get_theme_icon(SNAME("Favorites"), SNAME("EditorIcons")), TTR("Add to Favorites"), FILE_ADD_FAVORITE);
		}
		if (!all_not_favorites) {
			p_popup->add_icon_item(get_theme_icon(SNAME("NonFavorite"), SNAME("EditorIcons")), TTR("Remove from Favorites"), FILE_REMOVE_FAVORITE);
		}
	}
	if (p_paths.size() == 1) {
		const String fpath = p_paths[0];
#if !defined(ANDROID_ENABLED) && !defined(WEB_ENABLED)
		p_popup->add_separator();
		
		const bool is_directory = fpath.ends_with("/");
		const String item_text = is_directory ? TTR("Open in File Manager") : TTR("Show in File Manager");
		p_popup->add_icon_shortcut(get_theme_icon(SNAME("Filesystem"), SNAME("EditorIcons")), ED_GET_SHORTCUT("filesystem_dock/show_in_explorer"), FILE_SHOW_IN_EXPLORER);
		p_popup->set_item_text(p_popup->get_item_index(FILE_SHOW_IN_EXPLORER), item_text);
		if (!is_directory) {
			p_popup->add_icon_shortcut(get_theme_icon(SNAME("ExternalLink"), SNAME("EditorIcons")), ED_GET_SHORTCUT("filesystem_dock/open_in_external_program"), FILE_OPEN_EXTERNAL);
		}
#endif
		current_path = fpath;
	}
}
void FileSystemDock::_tree_rmb_select(const Vector2 &p_pos, MouseButton p_button) {