tools: use tokenless Codecov uploads

[targos]

Refs: https://docs.codecov.com/docs/codecov-tokens#uploading-without-a-token

I already enabled it in the Codecov settings for the nodejs org.

[nodejs-github-bot]

Review requested:

• @nodejs/actions

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.99%. Comparing base (e92499c) to head (22f5f49).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #55943      +/-   ##
==========================================
- Coverage   87.99%   87.99%   -0.01%     
==========================================
  Files         653      653              
  Lines      188091   188091              
  Branches    35941    35947       +6     
==========================================
- Hits       165516   165515       -1     
+ Misses      15751    15742       -9     
- Partials     6824     6834      +10     

see 26 files with indirect coverage changes

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests
• JS Bundle Analysis - Avoid shipping oversized bundles

[targos]

Rebased to reset the coverage-windows status (workflow is currently broken and has been disabled).