[release/8.0] Bump STJ and MSBuild Version

[steveisok]

Resolves CG alerts

[Copilot]

Pull Request Overview

This PR updates version numbers for System.Text.Json and Microsoft.Build packages to address component governance alerts, as part of maintenance for the release/8.0 branch.

• Updates System.Text.Json toolset version from 7.0.3 to 8.0.5
• Updates Microsoft.Build version from 17.8.3 to 17.8.29

[MichaelSimons]

cc @dotnet/source-build

@steveisok - I suspect these prebuilts are being detected because the corresponding Dependency entries in the https://github.com/dotnet/runtime/blob/release/8.0/eng/Version.Details.xml were not updated. For example, the Microsoft.Build dependency should be updated as well as the associated Microsoft.SourceBuild.Intermediate.msbuild dependency to the same commit and it's corresponding version. That is to say the dependencies from the same repo must be coherent.

[steveisok]

@MichaelSimons thanks for your help!

@dotnet/runtime-infrastructure there are enough bumps here that I would like one or more to do another review.

[jeffhandley]

Looks all right to me