refactor(tvix/store/pathinfoservice): make more generic

We don't need Arcs in most of the cases, we're fine with some container.

Change-Id: Ic4f8acb5b9d93e2b0923bb607463fb91e9d0e4fe
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10606
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>

tvix/store/src/pathinfoservice/grpc.rs

@@ -159,8 +159,8 @@ mod tests {
             let router = server.add_service(
                 crate::proto::path_info_service_server::PathInfoServiceServer::new(
                     GRPCPathInfoServiceWrapper::new(Box::new(MemoryPathInfoService::new(
-                        gen_blob_service().into(),
-                        gen_directory_service().into(),
+                        gen_blob_service(),
+                        gen_directory_service(),
                     ))
                         as Box<dyn PathInfoService>),
                 ),