Increase checkpoint timeout (MystenLabs#17831)

## Description 

As in title

## Test plan 

Ran against 100 seeds via the following:

```
CONSENSUS=narwhal ./scripts/simtest/seed-search.py simtest --test test_simulated_load_reconfig_with_crashes_and_delays
```

---

## 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:

crates/sui-core/src/checkpoints/checkpoint_executor/mod.rs

@@ -105,7 +105,7 @@ fn get_scheduling_timeout() -> CheckpointTimeoutConfig {
             std::env::var("NEW_CHECKPOINT_TIMEOUT_MS")
                 .ok()
                 .and_then(|s| s.parse::<u64>().ok())
-                .unwrap_or(if panic_on_timeout { 30000 } else { 2000 }),
+                .unwrap_or(if panic_on_timeout { 45000 } else { 2000 }),
         );
 
         CheckpointTimeoutConfig {