indexer: use sleep config for obj snapshot (MystenLabs#15874)

## Description 

title

## Test Plan 

CI

---
If your changes are not user-facing and do not break anything, you can
skip the following section. Otherwise, please briefly describe what has
changed under the Release Notes section.

### Type of Change (Check all that apply)

- [ ] protocol change
- [ ] user-visible impact
- [ ] breaking change for a client SDKs
- [ ] breaking change for FNs (FN binary must upgrade)
- [ ] breaking change for validators or node operators (must upgrade
binaries)
- [ ] breaking change for on-chain data layout
- [ ] necessitate either a data wipe or data migration

### Release notes

crates/sui-indexer/src/processors_v2/objects_snapshot_processor.rs

@@ -114,7 +114,8 @@ where
 
         loop {
             while latest_cp <= start_cp + self.config.snapshot_max_lag as u64 {
-                tokio::time::sleep(std::time::Duration::from_secs(5)).await;
+                tokio::time::sleep(std::time::Duration::from_secs(self.config.sleep_duration))
+                    .await;
                 latest_cp = self
                     .store
                     .get_latest_tx_checkpoint_sequence_number()