Bump @protobuf-ts/grpc-transport from 2.8.1 to 2.9.4

Bumps [@protobuf-ts/grpc-transport](https://github.com/timostamm/protobuf-ts/tree/HEAD/packages/grpc-transport) from 2.8.1 to 2.9.4.
- [Release notes](https://github.com/timostamm/protobuf-ts/releases)
- [Commits](https://github.com/timostamm/protobuf-ts/commits/v2.9.4/packages/grpc-transport)

---
updated-dependencies:
- dependency-name: "@protobuf-ts/grpc-transport"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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