chore(ci): Add protobuf linting

[erezrokah]

Looks like we can detect breaking changes to the protocol via https://docs.buf.build/ci-cd/github-actions

[yevgenypats]

I took a quick look at buf.build https://github.com/bufbuild/buf seems a bit of an overkill but didn't give it a try. do we really need this, also wasn't sure if it's paid or not?

[erezrokah]

Yeah, I was hoping this could be a nice new contribution. Since no one picked it up let's close this