[CI] Ensure smoke and npm test workflows validate successful runs

[chalin]

The suggestion here is to do something similar to what we do with OTel CI:

• Log build commands
• Inspect the build log:
  • Look for confirmation that tests ran to completion
  • No errors or warnings were reported

Followup to:

• [CI] Add smoke test via GitHub workflow #1776
• [CI] Consider adding smoke tests for building of Docsy itself #1777