maintenance(stjm): review test harness baseline

[github-actions]

Generated by the maintenance inventory on 2026-07-27T06:27:48Z.

Summary

The package test harness differs from the preferred xUnit v3 plus Microsoft Testing Platform baseline.

Findings

• coverlet.msbuild 8.0.0 in Egil.SystemTextJson.Migration/Directory.Packages.props
• Microsoft.NET.Test.Sdk 17.13.0 in Egil.SystemTextJson.Migration/Directory.Packages.props
• xunit.runner.visualstudio 3.0.2 in Egil.SystemTextJson.Migration/Directory.Packages.props
• xunit.v3 3.2.2 in Egil.SystemTextJson.Migration/Directory.Packages.props
• xunit.v3.mtp-v2 3.2.2 in Egil.SystemTextJson.Migration/Directory.Packages.props

Suggested Agent Task

• Inspect the current package, SDK, workflow, or test-harness docs before changing code.
• Make one focused PR for this issue.
• Keep package release-note conventions intact; use [skip notes] for internal maintenance if needed.

Acceptance Criteria

• The package either uses xUnit v3 plus Microsoft Testing Platform or documents why the classic runner remains.
• Coverage tooling remains compatible with the chosen runner.