chore: Use non-privileged build user `builder` for webtox build.

[iphydf]

This change is 

[netlify[bot]]

✅ Deploy Preview for olelo ready!

Name	Link
🔨 Latest commit	77e85c27385e4ebfc0456a66cc2a5452fdc19a7b
🔍 Latest deploy log	https://app.netlify.com/sites/olelo/deploys/64eb1e4037015100085abf99
😎 Deploy Preview	https://deploy-preview-37--olelo.netlify.app/
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[codecov[bot]]

Codecov Report

Merging #37 (77e85c2) into master (77a2b7e) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #37   +/-   ##
=======================================
  Coverage   41.17%   41.17%           
=======================================
  Files           7        7           
  Lines         221      221           
=======================================
  Hits           91       91           
  Misses        130      130