docs(tvix/castore): remove TODO

This probably was about passing around directory_putter at some point,
which we do, so whatever this meant, it's not actionable anymore.

Change-Id: I1b4e0cdd2119bf2b2a9cf06d186a3b476b0ff367
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9573
Reviewed-by: Linus Heckemann <git@sphalerite.org>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI

tvix/castore/src/import.rs

@@ -150,7 +150,6 @@ pub async fn ingest_path<P: AsRef<Path> + Debug>(
 ) -> Result<Node, Error> {
     let mut directories: HashMap<PathBuf, Directory> = HashMap::default();
 
-    // TODO: pass this one instead?
     let mut directory_putter = directory_service.put_multiple_start();
 
     for entry in WalkDir::new(p)