Update protoc

[CleanCut]

We are currently using protoc v3.17.0. This version was released on May 12, 2021 and there have been dozens of releases since then. We should update to a more recent version unless there is some reason we cannot.

[tuxy-streamer]

GitHub uses Ubuntu 24.04 as ubuntu-latest, so there seems no issue in updating to a stable release of protobuf-compiler.
I have tested all the workflow runs and have build it on my system (Arch Linux) with all the tests resulting to success.