build(deps): bump google.golang.org/grpc in /examples (#3943)

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.69.4 to 1.70.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.69.4...v1.70.0

)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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