build(deps): bump protobuf in /examples/grpc-bridge/client

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.15.7 to 3.17.0.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/master/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.15.7...v3.17.0)

Signed-off-by: dependabot[bot] <support@github.com>

examples/grpc-bridge/client/requirements.txt

@@ -1,4 +1,4 @@
 requests>=2.22.0
 grpcio
 grpcio-tools
-protobuf==3.16.0
+protobuf==3.17.0