fix(l2geth-verifier): only check last batch of the bundle

[colinlyguo]

1. Purpose or design rationale of this PR

In "finalize by bundle", only the last batch of each bundle is fully verified. This check still ensures the correctness of all batch hashes in the bundle due to the parent-child relationship between batch hashes.

2. PR title

Your PR title must follow conventional commits (as we are doing squash merge for each PR), so it must start with one of the following types:

• fix: A bug fix

3. Deployment tag versioning

Has the version in params/version.go been updated?

• Yes

4. Breaking change label

Does this PR have the breaking-change label?

• This PR is not a breaking change

[colinlyguo]

tested in a local testnet with Darwin transition:

curl -s -X POST 'http://localhost:8888' -H 'Content-Type: application/json' -d '{"jsonrpc": "2.0","id": 54321,"method": "scroll_syncStatus"}' | jq
{
  "jsonrpc": "2.0",
  "id": 54321,
  "result": {
    "l2BlockSyncHeight": 475,
    "l1RollupSyncHeight": 5209,
    "l1MessageSyncHeight": 5237,
    "l2FinalizedBlockHeight": 329
  }
}