Update dotnet SDK to latest published

[MattGal]

This change brings an up update to take a threading fix that could improve the symptoms of https://github.com/dotnet/core-eng/issues/13691.

See issue for details; this is not necessarily the definitive fix, but something we need to try as the available data points to this as a likely culprit.

To double check:

• The right tests are in and and the right validation has happened. Guidance: https://github.com/dotnet/core-eng/tree/master/Documentation/Validation

[ghost]

Hello @MattGal!

Because this pull request has the auto-merge label, I will be glad to assist with helping to merge this pull request once all check-in policies pass.

p.s. you can customize the way I help with merging this pull request, such as holding this pull request until a specific person approves. Simply @mention me (@msftbot) and give me an instruction to get started! Learn more here.

[garath]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[garath]

Closing this in favor of #7697.