DOC : updated n_jobs docs in Parallel class

[Schefflera-Arboricola]

fixes #1536

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.12%. Comparing base (6310841) to head (e99fc67).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1537      +/-   ##
==========================================
- Coverage   95.16%   95.12%   -0.04%     
==========================================
  Files          44       44              
  Lines        7562     7583      +21     
==========================================
+ Hits         7196     7213      +17     
- Misses        366      370       +4     

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

[tomMoral]

I don't think this is true.

The behavior of joblib depends on the backend through get_effective_n_jobs and there is no condition based on the number of CPUs.

The rational for not limiting the number of workers with the number of CPUs is that in some situation, a slight over subscription (using n_jobs > n_cpus) is beneficial.

[Schefflera-Arboricola]

Thanks @tomMoral!

[tomMoral]

Thanks for the PR, I did a small rewording, will merge this asap.