Rebrand and update for 5.0.1

[dougbu]

• [master] Update dependencies from dotnet/runtime dotnet/efcore ([master] Update dependencies from dotnet/runtime dotnet/efcore #26788)

  • 219ecd6

• when project template tests run test assets, need latest shared Fx bits

• hit BadImageFormatExceptions otherwise

  • test projects build against uploaded packages
  • those packages reference the 5.0.1 shared framework
  • the ASP.NET parts of the 5.0.1 shared Fx are crossgened to target Windows

• Use runtime and ref/ assemblies matching repo in Helix testing

  • add Directory.Build.*.in files based on project template test infrastructure
  • use files as import boundary where the project doesn't create its own Directory.Build.* files
  • ensure dotnet-watch tests also use the latest runtime and ref/ assemblies

• Extend Helix Directory.Build.* workarounds

  • generate Directory.Build.* files when restoring any projects
  • include generated files in Helix runs needing the latest runtime
  • copy generated files when testing dotnet-watch locally
  • include generated content in Microsoft.NET.Sdk.BlazorWebAssembly.IntegrationTests test assets
    • remove duplicate settings from existing Directory.Build.* files
  • ensure shared framework and targeting packs are laid out under .dotnet/ before test assets restore

• Disable crossgen when building for Helix runs

  • make $(CrossgenOutput) property override-able
  • use override in CI jobs that submit to other platforms
    • for now, leave the ARM64 Helix jobs alone (build on Ubuntu, run in Debian)

[dougbu]

We'll need this general improvement in the veracity of template tests when rebranding for 5.0.1. If others prefer, could take more of this from master e.g. turn off $(CrossgenOutput) in other pipelines or use the Directory.Build.*.in files in the Blazor SDK and dotnet-watch tests.

[dougbu]

This is blocked for now. Right @wtgodbe❔

[wtgodbe]

That's correct, 5.0.1 servicing will open up later this month

[dougbu]

This branch now includes everything that should be needed to get 5.0.1 builds going. I suspect it won't validate until the 5.0.100 SDK is usable in dotnet-install.* scripts. @dotnet/aspnet-build please review again since @wtgodbe only looked at one of the 6 commits here.