chore: use local @actions/artifact package for Node.js 24 testing

This branch uses a local file reference to @actions/artifact which includes
the updated @azure/storage-blob ^12.29.1 to fix the punycode deprecation
warning on Node.js 24.

This is a test branch - do not merge until @actions/artifact@5.0.1 is published.

Author: salmanmkc