Remove use of legacy images

[richlander]

It appears that this repo might be using old CentOS and Ubuntu images. Ubuntu 22.04 is the oldest Ubuntu version we support.

The old CentOS version seems to be coming from https://github.com/dotnet/fsharp/tree/release/dev16.11.

@ilyas1974

[T-Gro]

16.11 is VS 2019, are we expected to touch all of the historical release branches?

Is there an image moniker which we can rely on being stable and always supported, so that we do not need to touch older branches?

[richlander]

There isn't such a moniker. It also would not have worked well since CentOS doesn't exist anymore.

This branch is standing out as one of the few that is using an EOL OS.

[richlander]

The branch is still being built. Is that expected? We don't care about branches that are not built.

[T-Gro]

We occasionally need to service older release branches for support periods of SDK + VS, so we would love to have a mechanism to keep those branches buildable as long as we need to service the products related to them.

[richlander]

OK. Can you move to a different OS / version?

You can see that this image is 6 years old. It's actually not even relevant that the OS is EOL. The image is just old.

fsharp/eng/common/templates/jobs/source-build.yml

Line 17 in b6c2c4f

container: 'mcr.microsoft.com/dotnet-buildtools/prereqs:centos-7-3e800f1-20190501005343'

[KevinRansom]

@richlander

I'm going to close this issue, because Dev 16.11 ships .Net 5.0 which has reached it's end of life. We do not expect to manage updates to this branches engineering infrastructure through the open source F# repo. Dev16.11 will continue to ship .Net 5.0 and F# 5.0 --- All engineering maintainance for it will occur internally.

/CC @richlander , @T-Gro, @vzarytovskii , @abonie