Update `protobuf` Version

Description:

The current yamcs-client library specifies protobuf>=3.11,<4, which is causing dependency conflicts with other packages that require newer versions of protobuf. Specifically, opentelemetry-proto requires protobuf<6.0,>=5.0.

Request:

Could we update the protobuf dependency in setup.py to protobuf>=5.0,<6.0 to resolve these conflicts? The last 3.x version of protobuf was released in 2022, and using a more recent version could help avoid similar issues in the future.

[fqqb]

Has been on my todo list for a while, but at the same time, want to be careful to not break anything.

Some info on the differences:
https://protobuf.dev/news/2022-05-06/#python-updates

Can have a look soon to see if it's a straightforward switch or not.

Hi fqqb,

Perhaps tox lib could help you ensure that updating protobuf doesn't introduce any issues. It allows you to test the changes across different Python environments, which might give you more confidence in the update. If you need a hand setting it up, just let me know!

Best of luck with the testing!

[fqqb]

There's no tox here, but we do run some sanity checks as part of the GitHub Actions workflow.

I had a quick try at using Protobuf 5 generated code, in combination with a protobuf 5 runtime (latest versions for each), and that was working quite OK: generated code is totally different, but it behaves the same as before.

Some information on cross-version compatibility can be found here:
https://protobuf.dev/support/cross-version-runtime-guarantee/

It seems impossible to use protobuf 5 generated code, in combination with a protobuf 3 runtime (understandably). Our own environments are using protobuf 3.x.x from standard linux repositories, so I'll need to look into upgrading those, before continuing with this change.

This first experiment is available on pb5 branch of this repository.

Thanks for the detailed testing! I'll try out this branch as well and look forward to further updates.