build(deps): bump @hashgraph/sdk in /tools/whbar-hardhat-example

Bumps [@hashgraph/sdk](https://github.com/hiero-ledger/hiero-sdk-js) from 2.69.0 to 2.72.0.
- [Release notes](https://github.com/hiero-ledger/hiero-sdk-js/releases)
- [Changelog](https://github.com/hiero-ledger/hiero-sdk-js/blob/main/CHANGELOG.md)
- [Commits](hiero-ledger/hiero-sdk-js@v2.69.0...v2.72.0)

---
updated-dependencies:
- dependency-name: "@hashgraph/sdk"
  dependency-version: 2.72.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

tools/whbar-hardhat-example/package-lock.json

@@ -7,7 +7,7 @@
     "hardhat": "^2.26.1"
   },
   "dependencies": {
-    "@hashgraph/sdk": "^2.69.0",
+    "@hashgraph/sdk": "^2.72.0",
     "dotenv": "^17.2.1"
   },
   "overrides": {