[release/9.0.1xx] Fix tasks not loading on .NET Framework (#8952)

[ViktorHofer]

Partial backport of #8952

/cc @marcpopMSFT

This fixes a regression due to a TFM mismatch in msbuild task dependencies that was merged 10 days ago . The regression hasn't shipped anywhere yet but affects upcoming releases: release/9.0.106 up to 9.0.300.

Customer Impact

• Customer reported
• Found internally

The msbuild task assemblies from the Microsoft.TemplateEngine.Authoring.Tasks package throw the following exception when loaded with desktop msbuild (i.e. in VS):

C:\Users\vihofer.nuget\packages\microsoft.templateengine.authoring.tasks\10.0.100-preview.4.25215.8\build\Microsoft.
TemplateEngine.Authoring.Tasks.targets(14,5): error MSB4018: The "LocalizeTemplates" task failed unexpectedly. [C:\temp
\templmsbuild\templmsbuild.csproj]
C:\Users\vihofer.nuget\packages\microsoft.templateengine.authoring.tasks\10.0.100-preview.4.25215.8\build\Microsoft.Te
mplateEngine.Authoring.Tasks.targets(14,5): error MSB4018: System.IO.FileNotFoundException->Microsoft.Build.Framework.B
uildException.GenericBuildTransferredException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstracti
ons, Version=9.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The system cannot f
ind the file specified. [C:\temp\templmsbuild\templmsbuild.csproj]

Change the .NET Framework assemblies TFM from net481 to net472 so that the task project resolves the .NET Framework dependencies instead of the .NET Standard dependencies which have a different assembly version and need binding redirects.

Regression

• Yes
• No

Regressed with 7fa9bf9

Testing

Filed #8955 for comprehensive tests. Verified that the referenced assembly version now matches the deployed binaries assembly version for both msbuild task assemblies.

Risk

Medium - Changing the TFM of the .NETFramework assemblies in packages from net481 to net472.

[MiYanni]

Looks good, but something wrong with the version used in this branch according to the failing tests.

You must install or update .NET to run this application.