[infra] Use Artifacts Output layout

[martincostello]

Fixes #6256.

Changes

Use Artifacts Output layout to make build output easy to locate.

This has the additional effect of de-nesting the structure of the ZIP files containing the packages that are uploaded to GitHub Actions artifacts.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.75%. Comparing base (e21e9cc) to head (9570549).

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6301      +/-   ##
==========================================
- Coverage   86.76%   86.75%   -0.01%     
==========================================
  Files         258      258              
  Lines       11879    11879              
==========================================
- Hits        10307    10306       -1     
- Misses       1572     1573       +1     

Flag	Coverage Δ
unittests-Project-Experimental	86.37% <ø> (ø)
unittests-Project-Stable	86.67% <ø> (+0.03%)	⬆️
unittests-Solution	86.57% <ø> (-0.13%)	⬇️
unittests-UnstableCoreLibraries-Experimental	85.87% <ø> (+0.09%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 2 files with indirect coverage changes

[martincostello]

Need to investigate and fix the flakiness with the projects in the docs folder.

[Copilot]

Pull Request Overview

This PR refactors the build and packaging layout to use the new Artifacts Output layout, simplifying the structure of ZIP files and making build outputs easier to locate. Key changes include:

• Adding an Import of a centralized Directory.Build.props file in test, src, examples, and docs.
• Redirecting build output paths in PowerShell scripts to use a new artifacts directory.
• Updating GitHub workflow definitions to publish and validate packages from the new artifacts paths.

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
test/Directory.Build.props	Added Import to parent Directory.Build.props
src/Directory.Build.props	Added Import to parent Directory.Build.props
examples/Directory.Build.props	Added Import to parent Directory.Build.props
docs/Directory.Build.props	Added Import and opted out of Artifacts Output for docs
build/scripts/test-threadSafety.ps1	Updated the artifacts path for test build output
build/scripts/test-aot-compatibility.ps1	Redirected Publish path to the new artifacts layout for AOT compatibility test
build/Common.prod.props	Removed PackageOutputPath to transition to the new artifacts layout
Directory.Build.props	Added new properties for Artifacts Output configuration
.github/workflows/publish-packages-1.0.yml	Updated artifact paths from src to the artifacts directory
.github/workflows/package-validation.yml	Updated artifact paths from src to the artifacts directory

Comments suppressed due to low confidence (4)

build/Common.prod.props:20

• Removal of PackageOutputPath may cause unexpected publishing behavior if the artifacts output is not correctly redirected; please verify that the new configuration handles all legacy scenarios.

<PackageOutputPath Condition="$(Build_ArtifactStagingDirectory) != ''">$(Build_ArtifactStagingDirectory)</PackageOutputPath>

build/scripts/test-threadSafety.ps1:19

• [nitpick] Ensure that the updated artifacts path is accurate across environments and consistently used throughout the build scripts.

$artifactsPath = Join-Path $rootDirectory "artifacts/bin/$testProjectName/$($configuration.ToLowerInvariant())_$targetFramework"

.github/workflows/publish-packages-1.0.yml:83

• [nitpick] Confirm that the new artifact path aligns with the overall output layout and that the updated path correctly locates the packages for publishing.

path: ./artifacts/package/release

.github/workflows/package-validation.yml:33

• [nitpick] Verify that the new artifact directory is correctly accessible and that file permissions in the validation environment will not block artifact retrieval.

path: ./artifacts/package/release

[rajkumar-rangaraj]

Historically, this repo has avoided using a Directory.Build.props at the root and instead scoped props to src/, test/, etc. Introducing a root-level props file changes the MSBuild evaluation scope and might unintentionally affect folders like tools/, examples/, or future additions.

Would it be better to keep this scoped inside src/ or test/, and have src/test import it explicitly if needed?

[martincostello]

Artifacts output requires it to be at the solution root.

[rajkumar-rangaraj]

I agree with the artifacts folder, but I have concerns regarding Directory.Build.props.

[martincostello]

To not have that file at the root you're fighting the tooling because Artifacts Output specifically wants that file at that location to enable it. If you define the property elsewhere it generates an error and tells you to move it.

I did try putting it in the existing files, and then the output was in the wrong place and needed defining in multiple places. I was fighting the tooling.

Having the file at the root fits with the .NET SDK defaults and what someone uninitiated walking up to the repo would expect to find.