The single self-hosted act_runner intermittently fails actions/setup-dotnet:
a partial extraction sticks in the shared tool-cache (tar: Cannot open: File
exists) or the SDK tarball download corrupts. Install into a clean private
$HOME/.dotnet via dotnet-install.sh with a rm -rf + retry-once, matching the
npm ci and NuGet publish retries already in this pipeline.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>