refactor(tvix/store): use Box<dyn DirectoryService>

Once we support configuring services at runtime, we don't know what
DirectoryService we're using at compile time.

This also means, we can't explicitly use the is_closed method from
GRPCPutter, without making it part of the DirectoryPutter itself.

Change-Id: Icd2a1ec4fc5649a6cd15c9cc7db4c2b473630431
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8727
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

tvix/store/src/tests/utils.rs

@@ -8,13 +8,13 @@ pub fn gen_blob_service() -> Box<dyn BlobService> {
     Box::new(MemoryBlobService::default())
 }
 
-pub fn gen_directory_service() -> impl DirectoryService + Send + Sync + Clone + 'static {
-    MemoryDirectoryService::default()
+pub fn gen_directory_service() -> Box<dyn DirectoryService> {
+    Box::new(MemoryDirectoryService::default())
 }
 
-pub fn gen_pathinfo_service<DS: DirectoryService + Clone>(
+pub fn gen_pathinfo_service(
     blob_service: Box<dyn BlobService>,
-    directory_service: DS,
+    directory_service: Box<dyn DirectoryService>,
 ) -> impl PathInfoService {
     MemoryPathInfoService::new(blob_service, directory_service)
 }