refactor(tab): remove tabIndex set and unset for jsdom

[juanca]

What: Remove tabIndex management for tab method

Why: These pieces of code are not needed anymore with the current version of jsdom.

How: Removed and re-ran test suite.

Checklist:

• Documentation N/A
• Tests
• Typings N/A
• Ready to be merged
  

This is a followup from #368

[codecov]

Codecov Report

Merging #379 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #379   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           12        12           
  Lines          392       387    -5     
  Branches       113       111    -2     
=========================================
- Hits           392       387    -5     

Impacted Files	Coverage Δ
src/tab.js	100.00% <ø> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a270040...93704d5. Read the comment docs.

[kentcdodds]

Looks good to me. This may be a breaking change for people not on the latest version of jsdom which is a bit unfortunate. But I don't think we need a breaking change for it.

[kentcdodds]

🎉 This PR is included in version 12.0.7 🎉

The release is available on:

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

Your semantic-release bot 📦🚀