Test protobuf generation in CI

### Is your feature request related to a problem or challenge?

We recently had a regression that prevented us from generating protobuf source using protoc 3.12 and it went undetected in CI (the fix was https://github.com/apache/arrow-datafusion/pull/8603).

### Describe the solution you'd like

Add a CI check

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

No files or tests are named. Start by locating the existing CI configuration and the protobuf-generation entry point, then check how generation uses protoc 3.12. Done means CI detects a regression that prevents protobuf source generation.

Written by the indexing model from the issue text.