msbuild dogfood, pipeline modification attempt no 1.

[SimaTian]

{PR title}

• You've read the Contributor Guide and Code of Conduct.
• You've included unit or integration tests for your change, where applicable.
  • not applicable. We want to dogfood a MSBUILD feature against the current status. If we don't break anything that currently works, we're good to go.
• You've included inline docs for your change, where applicable.
• There's an open issue for the PR that you are making. If you'd like to propose a new feature or change, please open an issue to discuss the change or find an existing issue.
  • This is related to Enable MSBuild Server for partner .NET repos msbuild#11357

Description:

Attempting to set up the dogfood fos MSBUILD server before further rollout.

{Detail}
MSBUILD server is a feature of MSBuild that we're currently attempting to roll out. For that we kindly ask for help from our partner repositories to see if the feature is safe enough.

Fixes dotnet/msbuild#11357

[SimaTian]

I'm sorry for the confusion, I'm doing several repos and this one is already in progress. This PR is obsolete.