Update default xcopy-msbuild version in arcade

[dkurepa]

• This issue is blocking
• This issue is causing unreasonable pain

The arcade update to .NET 8 preview 4 requires MSBuild 17.6. We need to update our arcade templates so they use this new version.
The new version was generated using the scripts from https://github.com/jaredpar/xcopy-msbuild, but on MSBuild from VS2022.
The package also needs some other dlls to work correctly. I compared files to previous the previous working version, 17.4.1 and took what I needed from the VS2022 folder.
In the end, the 17.6.0-2 package was generated and it's use was validated in https://dev.azure.com/dnceng/internal/_build/results?buildId=2187291&view=logs&j=b11b921d-8982-5bb3-754b-b114d42fd804&t=fb192a8b-e433-5fc8-e2b0-276ab015e7d5

This issue is blocking arcade validation #13654

Release Note Category

• Feature changes/additions

Release Note Description

Update xcopy version in arcade scripts

[dkurepa]

PR: #13674
And a follow up issue #13676

[dkurepa]

The PR has been merged and it unblocked arcade-validation. I wrote a document on the wiki on how we can generate this package in the future.