Suppress simtest warnings (#17537)

## Description 

simple cleanup to address simtest warnings.

## Test plan 

How did you test the new or updated feature?

---

## Release notes

Check each box that your changes affect. If none of the boxes relate to
your changes, release notes aren't required.

For each box you select, include information after the relevant heading
that describes the impact of your changes that a user might notice and
any actions they must take to implement updates.

- [ ] Protocol: 
- [ ] Nodes (Validators and Full nodes): 
- [ ] Indexer: 
- [ ] JSON-RPC: 
- [ ] GraphQL: 
- [ ] CLI: 
- [ ] Rust SDK:

consensus/core/src/authority_node.rs

@@ -330,6 +330,8 @@ where
 
 #[cfg(test)]
 mod tests {
+    #![allow(non_snake_case)]
+
     use std::{collections::BTreeSet, sync::Arc, time::Duration};
 
     use async_trait::async_trait;

crates/sui-json-rpc-tests/tests/transaction_tests.rs

@@ -1,6 +1,7 @@
 // Copyright (c) Mysten Labs, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
+#[cfg(not(msim))]
 use std::str::FromStr;
 
 use move_core_types::identifier::Identifier;

crates/sui/tests/cli_tests.rs

@@ -4,9 +4,11 @@
 use std::collections::BTreeSet;
 use std::io::Read;
 use std::os::unix::prelude::FileExt;
-use std::str::FromStr;
 use std::{fmt::Write, fs::read_dir, path::PathBuf, str, thread, time::Duration};
 
+#[cfg(not(msim))]
+use std::str::FromStr;
+
 use expect_test::expect;
 use move_package::{lock_file::schema::ManagedPackage, BuildConfig as MoveBuildConfig};
 use serde_json::json;