Update remixicon sprite to v4.9.1

[tvdeyen]

Summary

Updates the vendored remixicon sprite from v3.4.0 (2,496 icons) to v4.9.1 (3,229 icons)

Checklist

Check out our PR guidelines for more details.

The following are mandatory for all PRs:

• I agree that my PR will be published under the same license as Solidus.
• I have written a thorough PR description.
• I have kept my commits small and atomic.
• I have localized any and all user-facing strings that I added to the source code.
• I have used clear, explanatory commit messages.

The following are not always needed:

• 📖 I have updated the README to account for my changes.
• 📑 I have documented new code with YARD.
• 🛣️ I have opened a PR to update the guides.
• ✅ I have added automated tests to cover my changes.
• 📸 I have attached screenshots to demo visual changes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.66%. Comparing base (1931ee8) to head (5bea062).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6438   +/-   ##
=======================================
  Coverage   89.66%   89.66%           
=======================================
  Files         990      990           
  Lines       20792    20792           
=======================================
  Hits        18644    18644           
  Misses       2148     2148           

☔ View full report in Codecov by Sentry.
📢 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.