chore(deps): bump @hiero-ledger/proto from 2.27.0 to 2.28.0 in /back-end in the hiero-sdk group (#2637)

chore(deps): bump @hiero-ledger/proto

Bumps the hiero-sdk group in /back-end with 1 update: [@hiero-ledger/proto](https://github.com/hiero-ledger/hiero-sdk-js).


Updates `@hiero-ledger/proto` from 2.27.0 to 2.28.0
- [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@v2.27.0...v2.28.0)

---
updated-dependencies:
- dependency-name: "@hiero-ledger/proto"
  dependency-version: 2.28.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: hiero-sdk
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

back-end/package.json

@@ -40,7 +40,7 @@
     "migration:revert": "pnpm typeorm migration:revert -d typeorm/data-source.ts"
   },
   "dependencies": {
-    "@hiero-ledger/proto": "2.27.0",
+    "@hiero-ledger/proto": "2.28.0",
     "@hiero-ledger/sdk": "2.82.0",
     "@nest-lab/throttler-storage-redis": "1.1.1",
     "@nestjs/axios": "3.1.3",