fix(tvix/castore/directory/tests): close upload handle

We need to ensure the Directories are successfully uploaded before doing
any testing with them.

Change-Id: Iafa8deb86b3d5eb302ebfba3ced34385f67a7229
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11244
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>

tvix/castore/src/directoryservice/traverse.rs

@@ -106,6 +106,8 @@ mod tests {
             .await
             .expect("must succeed");
 
+        handle.close().await.expect("must upload");
+
         // construct the node for DIRECTORY_COMPLICATED
         let node_directory_complicated =
             crate::proto::node::Node::Directory(crate::proto::DirectoryNode {