Tests run in 32-bit process

[rainersigwald]

MSBuild tests run in a 32-bit process for the .NET Framework MSBuild used in Visual Studio. That made sense when VS was 32-bit but we should consider changing it now.

This happens because of this

msbuild/src/Directory.Build.props

Lines 71 to 76 in 1698880

	<PropertyGroup Condition="$(TargetFramework.StartsWith('net4'))">
	<!-- When targeting .NET Framework, Exe and unit test projects build with x86 architecture if Platform is AnyCPU,
	and build for x64 architecture when Platform is x64 -->
	<RuntimeOutputPlatformTarget>x86</RuntimeOutputPlatformTarget>
	<RuntimeOutputPlatformTarget Condition="'$(Platform)' == 'x64'">x64</RuntimeOutputPlatformTarget>
	</PropertyGroup>

and

https://github.com/dotnet/arcade/blob/main/Documentation/ArcadeSdk.md#testarchitectures-list-of-strings