Fix OS support according to current EOL information

[Falco20019]

Relates to:

• Add support for Windows 11, version 24H2 #9523
• [macOS] Add support for macOS Sequoia #9470
• MacOS 12 ("Monterey") End of Support #9550

Also had a look at:

• Add support for Fedora 41 #9488 (this is not released yet, so I skipped it for now)

The following things have changed:

• Android released version 15 (added to .NET 6, 8 and 9)
• iOS, iPadOS and tvOS released version 18 (added to .NET 6, 8 and 9)
• iPadOS never had version 12 (removed from .NET 6, was iOS before on iPads)
• macOS released version 15 (added to .NET 6, 8 and 9)
• macOS ended 12 (moved to unsupported in .NET in .NET 6 and 8, removed from .NET 9)
• Windows 11 released version 24H2 (added to .NET 6, 8 and 9)
• Windows 11 ended 22H2 (W) and 21H2 (E) (moved to unsupported in .NET 6 and 8, removed from .NET 9)

Open points:

• Do we really want to have tvOS 12.2, 13 and 14 listed as supported? They are EOS but still supported to compile against. On Android we had a note mentioning the minimum possible target but only listed non-EOS versions as supported.
• Are new versions to be added to .NET 6 (since it's in Maintenance phase) or only EOS versions moved to unsupported?

/CC @richlander

Maybe tag with the os-support

[vitek-karas]

@dalexsoto for the Apple related version changes...
@jonpryor for the Android related version changes...

[vitek-karas]

/cc @matouskozak @ivanpovazan as FYI

[richlander]

Thanks! In general, LGTM.

Questions for the team:

• Are we supporting the new mobile OSes with .NET 6? I'm assuming not.
• It does appear that macOS 12 is EOL and that we should stop supporting it. Have me moved testing to macOS13+?

[dalexsoto]

Thanks! In general, LGTM.

Questions for the team:

• Are we supporting the new mobile OSes with .NET 6? I'm assuming not.
• It does appear that macOS 12 is EOL and that we should stop supporting it. Have me moved testing to macOS13+?

Hello! .NET 6 is no longer supported for mobile as it follows this support policy https://dotnet.microsoft.com/en-us/platform/support/policy/maui

[Falco20019]

Hello! .NET 6 is no longer supported for mobile as it follows this support policy https://dotnet.microsoft.com/en-us/platform/support/policy/maui

Good point, I will then revert the changes to Apple (besides macOS) and Android for .NET 6 and only remove the faulty iPadOS 12 entry there.

[richlander]

@Falco20019 -- We need to unsupport all Android and iOS versions for .NET 6. The rest looks good. Thanks!

[matouskozak]

• It does appear that macOS 12 is EOL and that we should stop supporting it. Have me moved testing to macOS13+?

A brownout will take place on November 4, 14:00 UTC - November 5, 00:00 UTC to raise awareness of the upcoming macOS-12 environment removal. For more details, see actions/runner-images#10721

In dotnet/runtime I think we already moved to macos-latest for internal builds and we will shortly have to move the public ones to 13+ as well.

[Falco20019]

@Falco20019 -- We need to unsupport all Android and iOS versions for .NET 6. The rest looks good. Thanks!

I unsupported .NET 6 MAUI and manually adjusted the Out of support OS versions to reference the MAUI policy since distroessed is currently not knowing about MAUI lifecycle requirements.

[xtqqczze]

Should macOS 12 be considered a previously supported OS for .NET 9, given that .NET 9 RC1 was supported from 2024-09-10 to 2024-10-08, but macOS 12 reached its end-of-life on 2024-09-16?

[richlander]

Should macOS 12 be considered a previously supported OS for .NET 9,

Either option works for me. I think that less than a month of support doesn't require us to do anything special. It's more academic than anything.

[richlander]

Thanks for the changes.

[Falco20019]

In my opinion, we don't need to add those supported before release to not clutter the JSON and MD files with Out of Support notes already on release. Personally, I would not even add them in the first place during previews and RCs, but that's also fine either way and might otherwise only confuse people during previews.