.NET: building the BlazorWeather app is slow

[rolfbjarne]

Repro:

• Clone https://github.com/danroth27/blazorweather
• dotnet build BlazorWeather.Maui -t:Run /bl
• Wait...

For me, the linker takes ~20 seconds:

      489 ms  Csc                                        3 calls
     1073 ms  ACTool                                     1 calls
     1848 ms  MSBuild                                   22 calls
     5429 ms  RestoreTask                                1 calls
    19462 ms  ILLink                                     1 calls

For other people (with different hardware), it can be much worse:

      323 ms  _ComputeManagedAssemblyToLink              1 calls
      352 ms  _CodesignAppBundle                         1 calls
      463 ms  GeneratePublishDependencyFile              1 calls
      611 ms  XamlC                                      1 calls
      638 ms  ResolveProjectReferences                   3 calls
    73156 ms  _RunILLink                                 1 calls

This is a "don't link" scenario (LinkMode=None), so it shouldn't take this long.

[marek-safar]

Moved the issue to dotnet/linker#2089