Protobuf generates different code locally and on CI

As it is hard to reason about what is the difference between local run and run on CI in the Docker container the first step to identify what is the actual difference between two. If it is only a formatting then it is possible that locally generated version was formatted and committed. To see the difference a new artifact 'proto.diff' would be available after failed execution of the 'no-changes' task. It will show delta between locally generated and committed files vs files generated on CI during verification.

Part of: #2855 (closed)

The example of the failed CI job https://gitlab.com/gitlab-org/gitaly/-/jobs/733981555 that has a new artifact proto.diff