fix: updates the paragon-theme.json output

[adamstankiewicz]

Description

Updates the paragon-theme.json output during npm run build to look like:

{
  "themeUrls": {
    "core": {
      "paths": {
        "default": "./core.css",
        "minified": "./core.min.css"
      }
    },
    "variants": {
      "light": {
        "paths": {
          "default": "./light.css",
          "minified": "./light.min.css"
        },
        "default": true,
        "dark": false
      }
    }
  }
}

Deploy Preview

Include a direct link to your changes in this PR's deploy preview here (e.g., a specific component page).

Merge Checklist

• If your update includes visual changes, have they been reviewed by a designer? Send them a link to the Netlify deploy preview, if applicable.
• Does your change adhere to the documented style conventions?
• Do any prop types have missing descriptions in the Props API tables in the documentation site (check deploy preview)?
• Were your changes tested using all available themes (see theme switcher in the header of the deploy preview, under the "Settings" icon)?
• Were your changes tested in the example app?
• Is there adequate test coverage for your changes?
• Consider whether this change needs to reviewed/QA'ed for accessibility (a11y). If so, please add wittjeff and adamstankiewicz as reviewers on this PR.

Post-merge Checklist

• Verify your changes were released to NPM at the expected version.
• If you'd like, share your contribution in #show-and-tell.
• 🎉 🙌 Celebrate! Thanks for your contribution.

[edx-semantic-release]

🎉 This PR is included in version 21.0.0-alpha.30 🎉

The release is available on:

• npm package (@alpha dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[edx-semantic-release]

🎉 This PR is included in version 22.0.0-alpha.1 🎉

The release is available on:

• npm package (@alpha dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[openedx-semantic-release-bot]

🎉 This PR is included in version 23.0.0-alpha.1 🎉

The release is available on:

• npm package (@alpha dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[openedx-semantic-release-bot]

🎉 This PR is included in version 23.0.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.02%. Comparing base (a2ac304) to head (65cfdc9).
Report is 907 commits behind head on alpha.

Additional details and impacted files

@@           Coverage Diff           @@
##            alpha    #2334   +/-   ##
=======================================
  Coverage   91.02%   91.02%           
=======================================
  Files         214      214           
  Lines        3534     3534           
  Branches      860      860           
=======================================
  Hits         3217     3217           
  Misses        309      309           
  Partials        8        8           

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