Cbc support: 2.10.x, document

[nhoening]

We use Cbc 2.9. That seems to be at least three years old, according to https://github.com/coin-or/Cbc/releases

We should upgrade to a newer version, 2.10.x, and see if it works. Then document that we seem to support both 2.9 and 2.10.

Do our scheduling tests cover Cbc usage?

[nhoening]

Looking at GithubActions output, we are already installing the latest stable (using apt-get):

Unpacking coinor-cbc (2.10.3+repack1-1build1) ...

So this ticket might just be about documentation only. Say which versions we have seen working, maybe also a comment in ci/install-cbc-from-source.sh.

[Flix6x]

As of August 2023, we are in the process of switching to the HiGHS solver. @nhoening can we can close this issue?

[nhoening]

It's still something we support using. I'll drop a comment in the ci file as I mentioned in this issue ...

[nhoening]

#783