Bump protobuf from 3.15.8 to 3.17.1

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.15.8 to 3.17.1.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/master/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.15.8...v3.17.1)

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