build(deps): bump protobufjs and google-gax (#167)

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

Updates `protobufjs` from 7.2.4 to 7.2.6
- [Release notes](https://github.com/protobufjs/protobuf.js/releases)
- [Changelog](https://github.com/protobufjs/protobuf.js/blob/master/CHANGELOG.md)
- [Commits](protobufjs/protobuf.js@protobufjs-v7.2.4...protobufjs-v7.2.6)

Updates `google-gax` from 4.0.3 to 4.3.2
- [Release notes](https://github.com/googleapis/gax-nodejs/releases)
- [Changelog](https://github.com/googleapis/gax-nodejs/blob/main/gax/CHANGELOG.md)
- [Commits](https://github.com/googleapis/gax-nodejs/commits/google-gax-v4.3.2/gax)

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

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