Include the aws region in example config (#19466)

## Description 

follow up to #19464 

---

## 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:

docs/content/guides/operator/archives.mdx

@@ -55,6 +55,7 @@ state-archive-read-config:
       # you can either provide your own aws credentials via "aws-secret-access-key" and
       # "aws-access-key-id" or set no-sign-request: true
       no-sign-request: true
+      aws-region: "us-west-2"
       object-store-connection-limit: 20
     # How many objects to read ahead when catching up  
     concurrency: 5