Bump protobufjs and google-gax

Bumps [protobufjs](https://github.com/protobufjs/protobuf.js) and [google-gax](https://github.com/googleapis/gax-nodejs). These dependencies needed to be updated together.

Updates `protobufjs` from 6.11.2 to 6.11.3
- [Release notes](https://github.com/protobufjs/protobuf.js/releases)
- [Changelog](https://github.com/protobufjs/protobuf.js/blob/v6.11.3/CHANGELOG.md)
- [Commits](protobufjs/protobuf.js@v6.11.2...v6.11.3)

Updates `google-gax` from 2.30.0 to 2.30.5
- [Release notes](https://github.com/googleapis/gax-nodejs/releases)
- [Changelog](https://github.com/googleapis/gax-nodejs/blob/v2.30.5/CHANGELOG.md)
- [Commits](googleapis/gax-nodejs@v2.30.0...v2.30.5)

---
updated-dependencies:
- dependency-name: protobufjs
  dependency-type: indirect
- dependency-name: google-gax
  dependency-type: indirect
...

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