[Consensus] increase min round delay in tests (#19644)

## Description 

It seems the default delay can result in too many commits per sec.
Also turn another per-commit log into debug, since we have not seen
related issues recently.

## Test plan 

CI

---

## Release notes

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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:
- [ ] REST API:

consensus/config/src/parameters.rs

@@ -19,7 +19,8 @@ pub struct Parameters {
     #[serde(skip)]
     pub db_path: PathBuf,
 
-    /// Time to wait for parent round leader before sealing a block.
+    /// Time to wait for parent round leader before sealing a block, from when parent round
+    /// has a quorum.
     #[serde(default = "Parameters::default_leader_timeout")]
     pub leader_timeout: Duration,
 
@@ -102,6 +103,9 @@ impl Parameters {
             // leading to long reconfiguration delays. This is because simtest is single threaded,
             // and spending too much time in consensus can lead to starvation elsewhere.
             Duration::from_millis(400)
+        } else if cfg!(test) {
+            // Avoid excessive CPU, data and logs in tests.
+            Duration::from_millis(250)
         } else {
             Duration::from_millis(50)
         }

consensus/core/src/core.rs

@@ -576,7 +576,7 @@ impl Core {
                 let Some(last_decided) = decided_leaders.last().cloned() else {
                     break;
                 };
-                tracing::info!("Decided {} leaders and {commits_until_update} commits can be made before next leader schedule change", decided_leaders.len());
+                tracing::debug!("Decided {} leaders and {commits_until_update} commits can be made before next leader schedule change", decided_leaders.len());
 
                 let mut sequenced_leaders = decided_leaders
                     .into_iter()