[main] Update dependencies from dotnet/arcade

[dotnet-maestro]

This pull request updates the following dependencies

From https://github.com/dotnet/arcade

• Subscription: 5b58eaee-79a7-4540-8274-08d8e9754760
• Build: 20210317.3
• Date Produced: 3/17/2021 7:18 PM
• Commit: 0ca849f0b71866b007fedaaa938cee63f8d056a6
• Branch: refs/heads/main

• Updates:
  • Microsoft.DotNet.Arcade.Sdk: from 6.0.0-beta.21105.12 to 6.0.0-beta.21167.3

[MichaelSimons]

This version of Arcade is upgrading the .NET toolset to 6.0. There appears to be some test projects that target .net5 which break.

Test Failure

It was not possible to find any compatible framework version
The framework 'Microsoft.NETCore.App', version '5.0.0' was not found.
  - The following frameworks were found:
      6.0.0-preview.2.21154.6 at [/datadisks/disk1/workspace/_work/1/s/.dotnet/shared/Microsoft.NETCore.App]

You can resolve the problem by installing the specified framework and/or SDK.

The specified framework can be found at:
  - https://aka.ms/dotnet-core-applaunch?framework=Microsoft.NETCore.App&framework_version=5.0.0&arch=x64&rid=ubuntu.16.04-x64
=== COMMAND LINE ===
"/datadisks/disk1/workspace/_work/1/s/.dotnet/dotnet" exec --depsfile "/datadisks/disk1/workspace/_work/1/s/artifacts/bin/Microsoft.DiaSymReader.Native.UnitTests/Debug/net5/Microsoft.DiaSymReader.Native.UnitTests.deps.json" --runtimeconfig "/datadisks/disk1/workspace/_work/1/s/artifacts/bin/Microsoft.DiaSymReader.Native.UnitTests/Debug/net5/Microsoft.DiaSymReader.Native.UnitTests.runtimeconfig.json"  "/datadisks/disk1/workspace/_work/1/s/.packages/xunit.runner.console/2.4.1/tools/netcoreapp2.0/xunit.console.dll" "/datadisks/disk1/workspace/_work/1/s/artifacts/bin/Microsoft.DiaSymReader.Native.UnitTests/Debug/net5/Microsoft.DiaSymReader.Native.UnitTests.dll" -noautoreporters -xml "/datadisks/disk1/workspace/_work/1/s/artifacts/TestResults/Debug/Microsoft.DiaSymReader.Native.UnitTests_net5_x64.xml" -html "/datadisks/disk1/workspace/_work/1/s/artifacts/TestResults/Debug/Microsoft.DiaSymReader.Native.UnitTests_net5_x64.html"  > "/datadisks/disk1/workspace/_work/1/s/artifacts/log/Debug/Microsoft.DiaSymReader.Native.UnitTests_net5_x64.log" 2>&1

@tmat - can you please take a look? A new arcade is needed to resolve #236 and unblock source-build.

cc @mmitche

[MichaelSimons]

FWIW - LGTM

[MichaelSimons]

@tmat - Friendly ask on who needs to review so that this can get merged?

[MichaelSimons]

Thanks @tmat!