### 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
Ref<Texture2D> file_icon;
	if (!p_is_valid) {
		file_icon = get_theme_icon(SNAME("ImportFail"), SNAME("EditorIcons"));
	} else {
		file_icon = (has_theme_icon(p_file_type, SNAME("EditorIcons"))) ? get_theme_icon(p_file_type, SNAME("EditorIcons")) : get_theme_icon(SNAME("File"), SNAME("EditorIcons"));
	}
	return file_icon;
}
bool FileSystemDock::_create_tree(TreeItem *p_parent, EditorFileSystemDirectory *p_dir, Vector<String> &uncollapsed_paths, bool p_select_in_favorites, bool p_unfold_path) {
	bool parent_should_expand = false;
	
	TreeItem *subdirectory_item = tree->create_item(p_parent);
	String dname = p_dir->get_name();
	if (dname.is_empty()) {
		dname = "res://";
	}
	subdirectory_item->set_text(0, dname);
	subdirectory_item->set_structured_text_bidi_override(0, TextServer::STRUCTURED_TEXT_FILE);
	subdirectory_item->set_icon(0, get_theme_icon(SNAME("Folder"), SNAME("EditorIcons")));
	subdirectory_item->set_icon_modulate(0, get_theme_color(SNAME("folder_icon_color"), SNAME("FileDialog")));
	subdirectory_item->set_selectable(0, true);