Update changelog for 2.7.0 release, upgrade CI

[luizirber]

• Update changelog for 2.7.0 release
• Replace unsupported CI actions with supported ones
• Use nextest and llvm-cov in CI

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.89%. Comparing base (45ee8ba) to head (773222c).
Report is 1 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master      #70       +/-   ##
===========================================
+ Coverage   79.27%   90.89%   +11.61%     
===========================================
  Files          12       10        -2     
  Lines         222     1010      +788     
===========================================
+ Hits          176      918      +742     
- Misses         46       92       +46     

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