I see that commit 2850ac5 from pull request #4756 is part of the v17.9.0-preview-23577-04 tag, yet even after upgrading the Microsoft.NET.Test.Sdk package to version 17.9.0-preview-23577-04 I'm still seeing the staircase issue. 🤔
Reproduction steps are the same as in the original bug report (#4754) with the following command between step 2 and 3:
dotnet add tests/Serilog.Formatting.Log4Net.Tests.csproj package Microsoft.NET.Test.Sdk --version 17.9.0-preview-23577-04