remove unused fields for bridge indexer (#19783)

## Description 

as title

## 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:
- [ ] REST API:

crates/sui-bridge-indexer/config.yaml

@@ -20,7 +20,3 @@
 # metric_url: <url>
 # Client metric port
 # metric_port: <port>
-# checkpoint size of each backfill worker, use 432000 for 1 worker per day, assume 5 checkpoint per second
-# back_fill_lot_size: <backfill lot size>
-# Optional starting checkpoint for realtime ingestion task
-# resume_from_checkpoint: <Sui checkpoint>

crates/sui-deepbook-indexer/config.yaml

@@ -16,7 +16,3 @@
 # metric_url: <url>
 # Client metric port
 # metric_port: <port>
-# checkpoint size of each backfill worker, use 432000 for 1 worker per day, assume 5 checkpoint per second
-# back_fill_lot_size: <backfill lot size>
-# Optional starting checkpoint for realtime ingestion task
-# resume_from_checkpoint: <Sui checkpoint>

crates/sui-deepbook-indexer/src/config.rs

@@ -17,7 +17,6 @@ pub struct IndexerConfig {
     pub deepbook_genesis_checkpoint: u64,
     pub concurrency: u64,
     pub metric_port: u16,
-    pub resume_from_checkpoint: Option<u64>,
 }
 
 impl sui_config::Config for IndexerConfig {}