chore(deps): update c8 to 12.0.0

[Renegade334]

This bumps c8's yargs dependency to v18, which resolves the module resolution errors when running CI with Node.js v26, and allows us to remove the package.json override.

The new package appearances in npm-shrinkwrap.json are due to other dependencies' own outdated yargs dependencies (for CLI functionality that we don't use) reappearing now that the override no longer affects them. I've separated out the two commits so as to make this clearer.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.54%. Comparing base (e4a7c7d) to head (62d0d6a).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1123   +/-   ##
=======================================
  Coverage   63.54%   63.54%           
=======================================
  Files          50       50           
  Lines        8507     8507           
=======================================
  Hits         5406     5406           
  Misses       3101     3101           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.