Align release workflow .NET SDK with repository (use 8.0.x)

[mfoltz]

Motivation

• Ensure the release publishing workflow uses the same repo-managed .NET SDK line as global.json, .codex/install.sh, and the main build workflow so published artifacts are built against the same toolchain and avoid accidental divergence.

Description

• Update .github/workflows/release.yml to set dotnet-version: '8.0.x', remove the dotnet-quality: 'preview' override, and add a short inline comment explaining the intentional alignment with the main build toolchain.

Testing

• Ran git diff --check which completed with no issues; attempted a YAML parse check using Python (yaml.safe_load) but it could not run because PyYAML is not installed in this environment.

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Codex Task

[Copilot]

Pull request overview

Updates the release publishing workflow to use the repository’s .NET 8 toolchain line, matching how CI builds are produced and reducing the chance of publishing artifacts with a divergent SDK.

Changes:

• Switch .github/workflows/release.yml from dotnet-version: 6.0.x (+ dotnet-quality: preview) to dotnet-version: 8.0.x.
• Remove the dotnet-quality: preview override.
• Add an inline comment documenting the intent to align with repo-managed SDK usage.