fix: deflake //rs/rosetta-api/icrc1:icrc_multitoken_rosetta_system_tests/multitoken_system_tests

Increase timeouts to handle resource contention when 4 tests run in parallel:

1. Increase MAX_ATTEMPTS in wait_for_rosetta_block from 20 to 60 (20s -> 60s)
   to give Rosetta more time to sync blocks under load.

2. Create RosettaClient with an explicit 120s timeout (instead of None which
   defaults to 60s) so make_submit_and_wait_for_transaction has sufficient
   time to find submitted transactions.

Root cause: With RUST_TEST_THREADS=4, multiple Rosetta + PocketIC instances
compete for resources, causing block sync and transaction confirmation to
take longer than the previous tight timeouts allowed.

Author: basvandijk

rs/rosetta-api/icrc1/tests/common/utils.rs

@@ -63,7 +63,7 @@ pub async fn wait_for_rosetta_block(
     network_identifier: NetworkIdentifier,
     block_index: u64,
 ) -> Option<u64> {
-    const MAX_ATTEMPTS: u8 = 20;
+    const MAX_ATTEMPTS: u8 = 60;
     let mut last_block = None;
     for _ in 0..MAX_ATTEMPTS {
         let response = rosetta_client.ready().await;

rs/rosetta-api/icrc1/tests/multitoken_system_tests.rs

@@ -401,9 +401,11 @@ impl RosettaTestingEnvironmentBuilder {
         )
         .await;
 
-        let rosetta_client =
-            RosettaClient::from_str_url(&format!("http://0.0.0.0:{}", rosetta_context.port))
-                .expect("Unable to parse url");
+        let rosetta_client = RosettaClient::from_str_url_and_timeout(
+            &format!("http://0.0.0.0:{}", rosetta_context.port),
+            Duration::from_secs(120),
+        )
+        .expect("Unable to parse url");
 
         let rosetta_ledger_testing_envs = futures::future::join_all(
             self.rosetta_ledger_testing_env_builders