Update RedHat 7 -> 8 -- release/6.0-staging

[richlander]

Red Hat no longer supports .NET 6 on RHEL 7.

Context: https://access.redhat.com/support/policy/updates/net-core

Also resolving #103380 (comment)

@omajid @akoeplinger

[omajid]

I don't know the format of these files too well, but the general change from 7 to 8 makes sense to me.

[dotnet-policy-service]

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

[carlossanlop]

No equivalent PR for release/8.0-staging?

[carlossanlop]

@richlander this is failing:

.packages/microsoft.dotnet.helix.sdk/6.0.0-beta.24360.7/tools/Microsoft.DotNet.Helix.Sdk.MonoQueue.targets(59,5): error : (NETCORE_ENGINEERING_TELEMETRY=Build) Helix API does not contain an entry for RedHat.8.Amd64.Open

Here: https://dev.azure.com/dnceng-public/public/_build/results?buildId=745875&view=logs&j=1f44e919-17d8-5098-631c-31ef11f9e57b&t=d617d884-da52-5b82-bd49-f7613b408af4&l=92

and here: https://dev.azure.com/dnceng-public/public/_build/results?buildId=745875&view=logs&j=bc8f69e2-91b3-518c-84f8-466a04c1af40&t=0864dbdb-cb3f-5f82-b0b6-057b78db53e2&l=92

[carlossanlop]

Approving for servicing as tell-mode. You can merge anytime if the CI looks good.

[richlander]

Silly me. I didn't realize that we didn't have a RHEL 8 queue. Tracking issue: dotnet/dnceng#3867.

I also didn't realize that they list was available: https://helix.dot.net/

[carlossanlop]

@richlander any updates on this? Is it ready to merge?

[richlander]

Thanks for checking in. The tracking issue is still open.

[carlossanlop]

BTW friendly reminder: Code Complete for the October Release is September 9. If we want this fix to be included in that release, please merge this PR before that date. Otherwise, it will have to wait until November.

[carlossanlop]

Removing servicing-approved to prevent accidental merge. @richlander feel free to add the label again when you're ready to merge (it will unblock the check-service-labels required CI leg).