Build NuGet packages in CI/PR pipelines (#40409)
* Build NuGet packages in CI/PR pipelines Removes `includePackageStage: false` from the PR pipeline templates so the package stage runs on every PR build, producing both `Microsoft.WSL.PluginApi` and `Microsoft.WSL.Containers` nupkgs as pipeline artifacts. This makes it easier to test SDK changes pre-merge. Tests are unaffected: the test stage still passes `includePackageStage: false`, so it continues to depend only on `build_x64` and downloads `drop_wsl_build` (not the package stage's outputs). The package stage runs in parallel with tests. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Update package job displayName to reflect NuGet output Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Ben Hillis <benhill@ntdev.microsoft.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>