Update download_private.sh (MystenLabs#12254)

## Description 

Fix typo in script

## Test Plan 

How did you test the new or updated feature?

---
If your changes are not user-facing and not a breaking change, you can
skip the following section. Otherwise, please indicate what changed, and
then add to the Release Notes section as highlighted during the release
process.

### 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

nre/download_private.sh

@@ -19,8 +19,8 @@ curl $url/sui-indexer -o sui-indexer
 curl $url/sui-node -o sui-node
 curl $url/sui-tool -o sui-tool
 
-echo "[+] Verifying sui docker artifacts for $commit_sha ..."
+echo "[+] Verifying sui binaries for $commit_sha ..."
 cosign verify-blob --insecure-ignore-tlog --key $pub_key --signature $url/sui.sig sui
 cosign verify-blob --insecure-ignore-tlog --key $pub_key --signature $url/sui-indexer.sig sui-indexer
 cosign verify-blob --insecure-ignore-tlog --key $pub_key --signature $url/sui-node.sig sui-node
-
+cosign verify-blob --insecure-ignore-tlog --key $pub_key --signature $url/sui-tool.sig sui-tool