### 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 (new_name.length() == 0) {
		EditorNode::get_singleton()->show_warning(TTR("No name provided."));
		rename_error = true;
	} else if (new_name.contains("/") || new_name.contains("\\") || new_name.contains(":")) {
		EditorNode::get_singleton()->show_warning(TTR("Name contains invalid characters."));
		rename_error = true;
	} else if (new_name.begins_with(".")) {
		EditorNode::get_singleton()->show_warning(TTR("This filename begins with a dot rendering the file invisible to the editor.\nIf you want to rename it anyway, use your operating system's file manager."));
		rename_error = true;
	} else if (to_rename.is_file && to_rename.path.get_extension() != new_name.get_extension()) {
		if (!EditorFileSystem::get_singleton()->get_valid_extensions().find(new_name.get_extension())) {
			EditorNode::get_singleton()->show_warning(TTR("This file extension is not recognized by the editor.\nIf you want to rename it anyway, use your operating system's file manager.\nAfter renaming to an unknown extension, the file won't be shown in the editor anymore."));
			rename_error = true;
		}
	}
	
	if (rename_error && tree->has_focus()) {
		s->set_text(col_index, old_name);
		return;
	} else if (rename_error && files->has_focus()) {
		return;
	}
	String old_path = to_rename.path.ends_with("/") ? to_rename.path.left(-1) : to_rename.path;
	String new_path = old_path.get_base_dir().path_join(new_name);
	if (old_path == new_path) {
		return;
	}
	if (EditorFileSystem::get_singleton()->is_group_file(old_path)) {
		EditorFileSystem::get_singleton()->move_group_file(old_path, new_path);
	}