[release/8.0] Upgrade CI from producing CentOS Stream 8 artifacts to CentOS Stream 9

[MichaelSimons]

Currently the runtime builds are producing CentOS Stream 8 artifacts e.g. dotnet-runtime-deps-8.0.9-centos.8-x64.rpm from this build. CentOS Stream 8 reached EOL 5/31/2024. The CI should be upgraded to product CentOS Stream 9 artifacts.

This is blocking other dotnet repos from migrating off of CentOS Stream 8 - example

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/runtime-infrastructure
See info in area-owners.md if you want to be subscribed.

[ericstj]

@agocke @jkoritzinsky is this as straight forward as updating https://github.com/search?q=repo%3Adotnet%2Fruntime+centos+path%3A*yml&type=code
Or do you typically need to make runtime or container changes too?

[jkoritzinsky]

We basically need to backport this PR: #103708

We need to decide what to do about the Centos Stream 8 assets though as this technically is a breaking change.

[ericstj]

Oh, I missed that this was an net8.0 specific issue. Could we add Centos 9 in net8.0? Would that unblock @MichaelSimons without breaking anything?

[jkoritzinsky]

We can backport to add the new assets, but we'd still be producing the Centos Stream 8 ones. @MichaelSimons is that okay or do we need to stop building the Centos Stream 8 assets as well.

[richlander]

Given that we are still in the first half of 8.0 lifetime, we really should try to trim assets that are not needed.

[MichaelSimons]

@MichaelSimons is that okay or do we need to stop building the Centos Stream 8 assets as well.

Adding Centos Stream 9 is all that is needed to unblock the SDK/installer testing.

Regarding Centos Stream8 artifacts. What is our policy around this? If we don't have one, we should create one. I can see producing them for a grace period but after that they should be dropped IMO. We can't test them so it feels strange/wrong to continue to produce them for the lifetime of a .NET release.