CI: GitHub is removing Ubuntu 20.04 LTS runners

[solardiz]

A CI job has just failed with:

This is a scheduled Ubuntu 20.04 brownout. Ubuntu 20.04 LTS runner will be removed on 2025-04-01. For more details, see https://github.com/actions/runner-images/issues/11101

GitHub did also send us an email about these planned brownouts before. I don't know why GitHub likes to keep breaking things (an attempt to conserve resources?)

Looks like we'll need to either stop testing with older compiler versions or setup usage of external Docker container images or something.

[claudioandre-br]

To raise awareness of the upcoming removal, THEY temporarily fail jobs using Ubuntu 20.04.

Today is a planned date for the brownouts. You have (almost) a month to decide what to do. But that's it.

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Well, the Ops team needs to maintain versions of macOS, Ubuntu, ... and Windows, without the support of Canonical, Microsoft, ...

I personally love removing old things/OSes.

[solardiz]

Sure, I understand what's happening and am not surprised. I just think that their decision to remove old runners is silly (but maybe I don't know some underlying reasons) and I am unhappy about either needing to spend time on setting up an alternative or giving up on portability testing to older compilers.