Removing uneeded Rc usages (linera-io#1618)

## Motivation

Doesn't seem to be needed, but please lmk if I'm missing something

## Proposal

Removing it

## Test Plan

CI

linera-indexer/graphql-client/tests/test.rs

@@ -2,13 +2,13 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use linera_service::util::resolve_binary;
-use std::{io::Read, rc::Rc};
+use std::io::Read;
 use tempfile::tempdir;
 use tokio::process::Command;
 
 #[test_log::test(tokio::test)]
 async fn test_check_indexer_schema() {
-    let tmp_dir = Rc::new(tempdir().unwrap());
+    let tmp_dir = tempdir().unwrap();
     let path = resolve_binary("linera-indexer", "linera-indexer-example")
         .await
         .unwrap();
@@ -32,7 +32,7 @@ async fn test_check_indexer_schema() {
 
 #[test_log::test(tokio::test)]
 async fn test_check_indexer_operations_schema() {
-    let tmp_dir = Rc::new(tempdir().unwrap());
+    let tmp_dir = tempdir().unwrap();
     let path = resolve_binary("linera-indexer", "linera-indexer-example")
         .await
         .unwrap();

linera-service-graphql-client/tests/test.rs

@@ -16,7 +16,7 @@ use linera_service_graphql_client::{
     applications, block, blocks, chains, request, transfer, Applications, Block, Blocks, Chains,
     Transfer,
 };
-use std::{collections::BTreeMap, io::Read, rc::Rc, str::FromStr, time::Duration};
+use std::{collections::BTreeMap, io::Read, str::FromStr, time::Duration};
 use tempfile::tempdir;
 use test_case::test_case;
 use tokio::{process::Command, sync::Mutex};
@@ -133,7 +133,7 @@ async fn test_end_to_end_queries(config: impl LineraNetConfig) {
 
 #[test_log::test(tokio::test)]
 async fn test_check_service_schema() {
-    let tmp_dir = Rc::new(tempdir().unwrap());
+    let tmp_dir = tempdir().unwrap();
     let path = resolve_binary("linera-schema-export", "linera-service")
         .await
         .unwrap();