Bump @grpc/grpc-js and google-gax

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

Updates `@grpc/grpc-js` from 1.7.3 to 1.8.17
- [Release notes](https://github.com/grpc/grpc-node/releases)
- [Commits](https://github.com/grpc/grpc-node/compare/@grpc/[email protected]...@grpc/[email protected])

Updates `google-gax` from 3.5.2 to 3.6.0
- [Release notes](https://github.com/googleapis/gax-nodejs/releases)
- [Changelog](https://github.com/googleapis/gax-nodejs/blob/main/CHANGELOG.md)
- [Commits](googleapis/gax-nodejs@v3.5.2...v3.6.0)

---
updated-dependencies:
- dependency-name: "@grpc/grpc-js"
  dependency-type: indirect
- dependency-name: google-gax
  dependency-type: indirect
...

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