Onboard to Arcade

[lbussell]

Part of #1855

This PR largely follows the Arcade Onboarding documentation, although it is a little out of date.

[lbussell]

When running ./eng/common/cibuild.sh or dotnet build from the project root, I get the following errors:

Restore complete (0.8s)
  Microsoft.DotNet.ImageBuilder net9.0 failed with 8 error(s) (0.3s)
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/.NETCoreApp,Version=v9.0.AssemblyAttributes.cs(4,12): error CS0579: Duplicate 'global::System.Runtime.Versioning.TargetFrameworkAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/Microsoft.DotNet.ImageBuilder.AssemblyInfo.cs(13,12): error CS0579: Duplicate 'System.Reflection.AssemblyCompanyAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/Microsoft.DotNet.ImageBuilder.AssemblyInfo.cs(14,12): error CS0579: Duplicate 'System.Reflection.AssemblyConfigurationAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/Microsoft.DotNet.ImageBuilder.AssemblyInfo.cs(16,12): error CS0579: Duplicate 'System.Reflection.AssemblyFileVersionAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/Microsoft.DotNet.ImageBuilder.AssemblyInfo.cs(17,12): error CS0579: Duplicate 'System.Reflection.AssemblyInformationalVersionAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/Microsoft.DotNet.ImageBuilder.AssemblyInfo.cs(18,12): error CS0579: Duplicate 'System.Reflection.AssemblyProductAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/Microsoft.DotNet.ImageBuilder.AssemblyInfo.cs(19,12): error CS0579: Duplicate 'System.Reflection.AssemblyTitleAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/Microsoft.DotNet.ImageBuilder/Debug/net9.0/Microsoft.DotNet.ImageBuilder.AssemblyInfo.cs(20,12): error CS0579: Duplicate 'System.Reflection.AssemblyVersionAttribute' attribute
  file-pusher net9.0 failed with 8 error(s) (0.1s)
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/.NETCoreApp,Version=v9.0.AssemblyAttributes.cs(4,12): error CS0579: Duplicate 'global::System.Runtime.Versioning.TargetFrameworkAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/file-pusher.AssemblyInfo.cs(13,12): error CS0579: Duplicate 'System.Reflection.AssemblyCompanyAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/file-pusher.AssemblyInfo.cs(14,12): error CS0579: Duplicate 'System.Reflection.AssemblyConfigurationAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/file-pusher.AssemblyInfo.cs(16,12): error CS0579: Duplicate 'System.Reflection.AssemblyFileVersionAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/file-pusher.AssemblyInfo.cs(17,12): error CS0579: Duplicate 'System.Reflection.AssemblyInformationalVersionAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/file-pusher.AssemblyInfo.cs(18,12): error CS0579: Duplicate 'System.Reflection.AssemblyProductAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/file-pusher.AssemblyInfo.cs(19,12): error CS0579: Duplicate 'System.Reflection.AssemblyTitleAttribute' attribute
    /Users/loganbussell/src/docker-tools/artifacts/obj/file-pusher/Debug/net9.0/file-pusher.AssemblyInfo.cs(20,12): error CS0579: Duplicate 'System.Reflection.AssemblyVersionAttribute' attribute

Build failed with 16 error(s) in 1.4s

./eng/common/build.sh appears to do nothing.

@MichaelSimons or @akoeplinger - any suggestions here?

I think this one is solved for now. Needed to clean my local build.

[lbussell]

Next error:

  Microsoft.DotNet.ImageBuilder failed with 1 error(s) (0.6s)
    CSC : error CS8002: Referenced assembly 'Cottle, Version=2.0.10.0, Culture=neutral, PublicKeyToken=null' does not have a strong name.

I thought strong naming isn't needed for .NET 5+. I don't think this project cares about building packages for netstandard and definitely not .NET Framework. I was thinking we'd probably target net8.0 or net9.0.

/cc @mmitche